So I'm working on a small-time game, a SHMUP that currently allows four modes of play with the ultimate intent of having eight unlockable characters. The game uses the GBC palette restrictions, including tile manipulation, but the screen uses a custom resolution (320*240 as opposed to 160*144). I'd like some feedback on the themes aimed for in these mockups (e.g. what iconography could be implemented/embellished) as well as the colour balance (which combinations work well, which could be improved/replaced/saturated/etc). If you'd like more information on the project, whether that will help inform your opinion or simply for curiosity's sake, feel free to ask.

Each stage mockup features a different playable character and [non-playable anatagonist].



From left to right: ancient ruins [skeleton ninja], moonlit city [dragon knight], abandoned warehouse [botched superhero experiment], sea bridge [mobile ferris wheel]