Nice idea and execution. Pure red/blue is maybe not the best colour scheme, but I think it works better than it has any right to. The audio is also quite nice.
As already mentioned by others, it doesn’t seem to be possible to jump off an edge by pressing D + Space. Instead, you plunge to your death.
In would also be nice to start at the beginning of the current level after death, instead of the level selection screen.
It is nevertheless a fun game (albeit sometimes frustrating).