It's been a long time since I played this hack, and yes, it qualifies as Nintendo Hard. However, the only cheat code I actually used was the Walk Through Walls code, and only for the seventh gym, because screw wasting however many hours it takes to figure out how to get past those damn sliding boulders.
While I myself didn't use this, after the seventh gym you can obtain one of the game's Pickup users, which would make the rest of the main game somewhat easier since Rare Candies can be used as Revives outside of battle.
Also, Nimbleaf is the best starter IMO, though you'll have to grind it to around Level 33 (if not 36 to reach its final form) and get a little lucky if you don't want to get swept by the Water gym's lead Starmie. And grinding is much more time consuming than on most hacks.
My endgame team for the first E4 run was Caudaleaf, Houndoom, Hantama, Walrein, Lilapse, and Zapdos, the last one being built to tank special attacks. Looking back on it, I don't like that I ended up using multiple legendaries, but considering that Lilapse is one of only a few Ground-types that doesn't lose to most Electric-types...
Recap of some of the things I strongly dislike, if not hate, about this hack:
1) Machu. What the actual hell were the original makers smoking when they came up with that monstrosity? I hope this Fakemon gets deleted from the sequel, if there is actually going to be a sequel.
2) The distribution of high-powered coverage moves with minor or irrelevant drawbacks. The majority of Electric-types getting Hydro Pump, for example, makes way too many Ground-types in Vega unusable in their original role as an Electric counter, and competitively, only Dugtrio, Garchomp and Lilapse would be OU-worthy if a metagame for Vega existed (and Garchomp might get banned to Ubers in Vega's metagame like it did in Gen 4). (Edit: After going through the data files, I remembered that Mamoswine is in Vega along with three others that have a good shot at OU: Dvaarak (Arena Trap), Hasaga, and Pinchor. *smacks myself for forgetting about Mamoswine and Pinchor*)
3) Phantonate. It is incredibly broken, due to getting the two most broken abilities in the game, Shadow Tag and Wonder Guard, while having an HP stat that's higher than 1 along with good enough Attack and Speed to abuse its abilities.
4) Zapdos doesn't learn Thunderbolt. WTF.
5) Being unable to figure out how to breed Earthquake onto Gible, if it's even possible to do so like the data files claim.