Hello all. I’ve been doing personal rom-hacks up to the 3rd gen for my own playthroughs for years. This hack has been completed for two months and I feel it’s good enough for everyone to enjoy, so I’m sharing it now.
I’ve been a fan of Pokémon Yellow since forever (my introduction to the franchise!) and I still love it to death. Way harder than Red and Blue , it also added some much-needed updates (why can’t Charizard learn Fly in R/B ???) and… bestspriteseverfightmeirlifyoudisagree. But let’s be honest, 20 years later, it has aged a lot, especially considering the game’s mechanics. Teambuilding is average, the game is unbalanced, choices are limited and lots of Pokémon are useless because of weird stats distribution or lacking movepools (hurray… pinsir learns… no bug moves!!). Anyway you know what I mean, Gen 1 was broken.

Thus, I created this hack so I could have an optimal experience playing Yellow with much more challenge and options. However, I also play Yellow for its simplicity and straight-forwardness, so I mostly kept it old-school (no p/s split sorry). I feel that too much new features and mechanics that are too modern would make the experience too much different from Yellow. Be sure to check the full documentation to know what I changed/added.

Features:

• All 151 obtainable! This seems to be a best-seller among this style of hacks lol. Some are available via in-game trades or other “special” means. Of course, every Pokémon can evolve to its final stage without the need to trade. Even your starter Pikachu evolves (by level). Some Pokémon evolve sooner. Wild Pokémon have been modified with an emphasis on variety. You can get useful Pokémon and varied teams since the beginning (without it being too broken). Check the documentation for full locations.

• Optimisation of Pokémon. A good chunk of the Pokémon had their stats boosted or rearranged and learn new and fitting moves/TMs. Some had their type changed for versatility (Kingler Water/ground, etc.), coolness factor (Ninetales Fire/Ghost, etc.) or just correcting what should have been done since the beginning (did you know Golduck wasn’t psychic? Yeah not anymore here). Keep in mind that this is only done for the sake of keeping the game more balanced and bringing Pokémon to their full potential, like Scyther learning decent moves. I’m not trying to break the game, no one had their stats boosted like crazy, except for the weakest ones like Farfetch’d or Porygon (which are decent now). Check the documentation for more on this.

• New attacks / TMs / boosts to old moves. I added (let’s say “replaced useless moves”) 23 moves from other gens to the game, as to have offensive bug/ghost/dragon attacks but also expanding the movepools of the Mons. Megahorn, Air Slash, Outrage, Brick Break, Sludge Bomb, Nasty Plot, Drill Run, Outrage… I also edited 30 moves for balance. Egg Bomb is Grass, Gust is Flying, Rock Slide is more accurate, etc. Finally, I changed 19 of the TMs and made most of the useful ones available in stores.

• More challenge. The opponents now have higher-leveled Pokémon and varied teams. I never understood why Team Rocket’s roster of Pokémon was pretty much only Zubat and Rattata, they steal Pokémon so they should have access to nearly everything. Also, no-more level 45 unevolved Pokémon, near the middle every opponent's Pokémon is evolved. The Boss battles are harder now, with them having more Pokémon, varied teams and their own movesets.

• Other quirks like: type match-ups now up to date (did you know bug was weak to poison? Not anymore now); new prizes at the Celadon Game Corner ; new in-game trades ; some items like PP Up being sold (at a high price)…

All in all this hack was made by a hardcore Pokémon fan for other hardcore Pokémon fans. If you’re looking for the most technically advanced Yellow hack with the split and repel system and whatnot, this might not be the best for you. But if you want to revisit Yellow with more challenge and fairness, while still keeping the feel old-school, check this out.

Screenshots:



Download & Documentation:



Bugs:

I only noticed one bug that’s not very annoying but that still should be mentioned: When a Pokémon evolves, its stat become very odd. That is until it gains a level, or is deposited in the computer, where its stats adjust and become normal. I’d be glad to have some help to fix this.

The hack was done 100% by myself with the pokeyellow disassembly.

Thanks for checking and playing!

I was just looking for a 151 hack for Pokemon Yellow lol. Trying this right now. Thanks for this game :) (Banner looks cool btw)

Just came up on a glitch with hm02 because when i have it in my bag i cant go Below the hm to my other items

Hey-- sorry for not replying sooner. Uhh, that's odd, I checked it on another run and I didn't have this problem. I did expand the bag capacity in the hack though, so maybe there's something I messed up... I don't think so, to be honest. Have you tried storing HM02 on the PC and getting it back? or changing the order of the item in your bag with Select?

Other than that, how do you like the game so far? I'd be happy to have some feedback.

It would be cool for a bigger postgame if at all possible. With these rebalances this would be great for a battle fronteir or something else similar to that to be added in. Also the mirror download is broken

I appreciate this hack being made and am enjoying it a lot thus far. It's fun playing with the changed stats and moves. Thank you for making it 212 Thug.

Honestly this game feels way too easy for me. It would be cool if there was a high difficulty version that included features like level scaling, forced set mode, no in battle items, etc. Maybe turn off stat exp. Giving so many Pokemon access to Nasty Plot might be too cheap.

I second the notion of adding a post-game of some sort. It's not necessary, but other bonuses, like more rivals, or a battle with Prof. Oak or something would be cool.

My Aerodactyl can't learn Earthquake even though your documentation states he should be able to. Would you kindly correct this?

Aloa, so far i enjoyed playing your hack immensely.

Pokemon Evolution screws up their stats, sometimes resulting in a few abyssimal stats (like base value 0) and at other times with ridiculously high values (just evolved [email protected] 30, and kabutops has At/De/Spc all over 140). This is more like a small annoyance than gamebreaking, since any action that recalculates stats reverts this to normal and expected values.

I am looking forward to seeing the endgame that you designed, however i am somewhat suspicious about some changes to already strong pokemon (like, how ridiculous is Dragonite with Phys/Spec STAB moves?)

I am withholding balance feedback for now, although i too think leveling is too easy, so a level difference based XP gain could be a simple solution.

The effort you put into creating is hack is quite appreciated (together with your corresponding intent)!
Thanks, Love, Aloa!

Please tell me where Dratini can be found?

Loved the game. Just beat the Elite 4 last night.
Had to read up on the evolution glitches as well cuz they were very confusing when I didnt know about them. The only things I found worth noting that I couldn't find anything written about, (that might have been errors) were the fact that:
1. Dragonite Cant learn fly even though hes flying type. That was kind of irritating considering i planned him from dratini to have fly at lvl 45.
2. Cut is bug type. Cool change for sure, giving a nice counter to the psychic types out there, but not alot of pokemon were able to learn such an important move to get around and I found that irritating. Ended up having to teach mew cut :/.
All in all, I had a good time. Beat the elite four with low lvl 50s pokes (Jolteon, Kabutops, Poliwrath, Mew, Dragonite, and Snorlax). Loved the increased difficulty, but Surprisingly I think it could be even harder. I didnt really rely heavily on items either. Just utilizing stab and type effective knowledge mostly. was able to make some good sweepers with amnesia/nasty plot/swords dance as well if needed. All in all, Id say its a 8/10 because of the bugs/confusion with dragonite/fly and Cut/bug type, but if everything was seamless with no surprises, id say 9/10.

Thanks for putting in the work to make this man! This was my first time playing a gen 1 hack and I loved it :)

you can find him with a super rod in the safari zone or at the game corner for 1500 credits

Thanks for answering my question. :)

Hello all, thanks a lot for the feedback and reporting some errors. I corrected some mistakes, like Aerodactyl not learning Earthquake or Dragonite not learning Fly. I might have forgotten ~some~ other moves but I'm not sure so I'd be happy if you could notify me if you find other mistakes.

Concerning the difficulty and a post-game:

I don't think I'll implement a post-game in this rom, for many reasons, but if any of you hackers want to develop on this rom and add a post-game I'm open. But know that I won't help besides general ideas because 1) I suck at hacking lol 2) I don't have time to work on this apart from correcting mistakes that you point out or that I identify.
Also I think I never even thought about a post-game because I wanted to keep the Yellow experience complete. But I reckon a last secret battle with Oak would be cool lol.

I tried to make the game more difficult. By this, I mean that all the special battles have been buffed, from gym leaders to Jessie James or the Elite 4. All the levels have been upped, some teams have been slightly altered (more pokemons, some different ones, more efficient movesets). I kept a relatively consequent level gap between the trainers of an area and the "boss" of this one as to not end up overleveled in those battles. HOWEVER keep in mind that the original Yellow's AI sucks. You might remember the Lance battle in twitchplaysred where his level 62 Dragonite lost against a lv 32 Venomoth because the Dragonite kept spamming Barrier and Agility instead of attacking... because those moves are psychic and Venomoth is poison, the AI identified them as super-effective. The problem is that the AI didn't make a difference between status and offensive moves and it ended choosing the psychic types even tho they weren't offensive (FYI the 2 other moves are Slam and Hyper Beam). SO when the last Pokémon of the semi-final boss has an AI like this, I don't think that my boost of his levels and moves will be fully exploited by the AI. BUT STILL the fights are harder now. Rival's Pokémon in endgame are level 70-73.
To ablahblah987: Set mode and No items are a player's choice and not an obligation I think. I mean you can trigger set mode in the options and you can avoid using items as a rule, so you can actually play like this if that's what you want.

I also made some minor changes, like slight alterations in some learnsets (nothing drastic) or in wild Pokémon (again nothing too different, just more balance and made some Pokémon less difficult to encounter or catch).
I still don't know what causes evolution to screw up the stats for a while though. I don't think it's that much of a trouble as leveling up the Pokémon once or depositing it in the PC will turn back the stats to normal.

Anyway I present to you Pokémon Opti-Y V.1.1. I also updated the first post with the links.

Download & Documentation:

Hello all, thanks a lot for the feedback and reporting some errors. I corrected some mistakes, like Aerodactyl not learning Earthquake or Dragonite not learning Fly. I might have forgotten ~some~ other moves but I'm not sure so I'd be happy if you could notify me if you find other mistakes.

Concerning the difficulty and a post-game:

I don't think I'll implement a post-game in this rom, for many reasons, but if any of you hackers want to develop on this rom and add a post-game I'm open. But know that I won't help besides general ideas because 1) I suck at hacking lol 2) I don't have time to work on this apart from correcting mistakes that you point out or that I identify.
Also I think I never even thought about a post-game because I wanted to keep the Yellow experience complete. But I reckon a last secret battle with Oak would be cool lol.

I tried to make the game more difficult. By this, I mean that all the special battles have been buffed, from gym leaders to Jessie James or the Elite 4. All the levels have been upped, some teams have been slightly altered (more pokemons, some different ones, more efficient movesets). I kept a relatively consequent level gap between the trainers of an area and the "boss" of this one as to not end up overleveled in those battles. HOWEVER keep in mind that the original Yellow's AI sucks. You might remember the Lance battle in twitchplaysred where his level 62 Dragonite lost against a lv 32 Venomoth because the Dragonite kept spamming Barrier and Agility instead of attacking... because those moves are psychic and Venomoth is poison, the AI identified them as super-effective. The problem is that the AI didn't make a difference between status and offensive moves and it ended choosing the psychic types even tho they weren't offensive (FYI the 2 other moves are Slam and Hyper Beam). SO when the last Pokémon of the semi-final boss has an AI like this, I don't think that my boost of his levels and moves will be fully exploited by the AI. BUT STILL the fights are harder now. Rival's Pokémon in endgame are level 70-73.
To ablahblah987: Set mode and No items are a player's choice and not an obligation I think. I mean you can trigger set mode in the options and you can avoid using items as a rule, so you can actually play like this if that's what you want.

I also made some minor changes, like slight alterations in some learnsets (nothing drastic) or in wild Pokémon (again nothing too different, just more balance and made some Pokémon less difficult to encounter or catch).
I still don't know what causes evolution to screw up the stats for a while though. I don't think it's that much of a trouble as leveling up the Pokémon once or depositing it in the PC will turn back the stats to normal.

Anyway I present to you Pokémon Opti-Y V.1.1. I also updated the first post with the links.

Download & Documentation:

Hey, I really like your hack! I was hoping you'd be willing to upload the github source. I was wanting to change the max_level to 250. I hate having level 100 as the cap personally. :/

If you'd rather not make the github accessible, could you change that one part and make a separate version?

sorry 212 thug but your links are dead alternative links:
https://drive.google.com/file/d/1CWUkB9FGoDP3qrBkHfJgWQP6fyArWy9w/view
https://drive.google.com/open?id=1ngQTh_bt-SrbivIBNnnvLEGmTTKJ4sM7
if somebody needs the rom please PM me thanks

Thank you 212 Thug. Thanks for your hardwork. Whether or not you're still active in the forum, we will always give you the greatest support. Thanks :)

Links aren't working

Links aren't working anymore :(
Does anyone have the files??

Hey! Both documentation and download on the MEGA thing says that the link is either invalid or terms of service deleted it. I really wanna play this!

Hey! Both documentation and download links don't work, I really wanna play this!