Generally I don't like asteroids kind of games
but it's ok, that green filter and graphic style gives feeling that user is playing on old TV. I played it only a few minutes and didn't found any bugs that would be visible in short session.
As You have already experience and framework with such kind of games consider something more complicated: many years ago I saw some unfinished/early stage project made with Allegro game library and pixel-art graphic - combination of Space Invaders and Tower Defense genre, something that was used already by many other games. You build different towers on ground to protect Your base from invading aliens, that are moving like in SI games, there are boss fights, you get $$, can upgrade towers and so on. Something like this would be perfect for mobiles
