This guy in Fuchsia City uses a bunch of all caps WORDS in his dialogue.
One of the machines in Silph Co. can be walked through.
Giovanni uses the wrong pronoun when referring to a female character.
More capitalization.
Cinnabar Island npc still has dialogue about multiplayer features that were removed.
Dialogue suddenly becomes colored when restoring a fossil.
More CAPITALIZATION.
Nothing happens when you try to talk to the guard between Fuchsia and Route 19.
You shouldn't be able to walk here.
After beating Blaine, Red's dialogue is normal, except when you think he's done talking, it goes crazy.
You sort of clip through objects in Cerulean Cave.
Another gender issue?
The two tiles to the right of the player can't be walked on.
The Pokemon League's doors don't open. You just phase through them. The door of other buildings open.
More colored text.
Each starter has two sprites in the credits, and the colors of the second one are wrong. I thought this might be intentional, but it doesn't happen in vanilla Firered:
https://youtu.be/cgdRqMkz_X8?t=119
You can't reach the kid on the right in Vermillion City to talk to them.
Battle Zone: you can't walk on the row of grass below me.
There's no apparent way to reach this item. But I got it anyway, since you can to walk off the northern cliff. The entire row of tiles above the island can be walked on from the island.
All the east-west staircases in the Battle Zone look like this. Each is one tile off from the ones next to it, so you have to zigzag down the stairs instead of walking straight up and down like you can for any other long staircase.
Shouldn't be able to walk here.
Things I'm not sure about:
I caught both Heatran and Deoxys with one ultra ball, which would be pretty damn unlikely if they both had catch rates of 3.
Blaine talked about how having his badge would increase the special stats of your pokemon. I don't remember the other gym leaders talking about it, and the guy in Cerulean who talks about the badges is gone, so I assumed that mechanic was removed in this hack. I haven't gone back to the other gym leaders to be sure though.