This is a mod/hack for the real GBA Doom 1 game. Like in PSX Doom The Lost Levels TC, I've added all Doom 1 levels which not included in original GBA Doom release.
Thank you for making this! Just tested it and looks pretty awesome. Works perfect on my GAME BOY micro!
I increased the rating from 8 to 10 because some years later this has become a classic for me. It has some minor bugs, but it's still a mod that I like to replay every one or two years.