This game was one of my favorites back in the 2000s, playing lots of games scraped form uDevGames competition on the family G5. The movement in this game, momentum-based damage, walljumping, knockback from your shot, all are just seared into my mind. I'm glad to have found it hosted again! (I couldn't for the life of me remember the name; had to do some 'udevgames stomp robot' searching after failing to find it on archive.org crawls)
The repulsive force above the bordering buildings really felt like it could be overcome if I juuuuust managed to build up enough steam - then I could fly over the cityscape at my hearts content. The movement alone is a game in itself - I would love some infinite scrolling version of this game, perhaps with a refresh/cooldown on the upwards flight to put some rails on. In any case, I really hope someday you can revisit the idea and build it out further. This is the good stuff.