Pokemon Red also seems supported; haven't tried others.

What I find particularly amusing is that (not surprisingly) GPT-4 doesn't really enforce rules. If I want a Pikachu as my starter pokemon, I can get one. (That said it does seem to enforce limits on buying items)

Edit: Other games seem to work as well. I just started playing a CLI Deus Ex which correctly starts on Liberty Island and roughly has the correct mechanics.