The chip graphics were nice, but in general everything was pretty empty and abstract. The player and all the bullets, even yours being the same color... well it's readable, because you and yours are small and on a track, but it isn't very visually interesting, even if it is thematic. The music was nice, if a bit on the shorter side for a loop.
I never quite understood how the player decided which direction to face when it wasn't part of the the rotation pattern. Like after you move down a direction, or got to a fresh intersection. Other than one corner where it seems like you don't turn the right way immediately at an intersection, it didn't really effect play that much. Most of the levels were very easy. Though if you did die, the game did not handle respawning gracefully at all, breaking in various ways. Something isn't being reset correctly there.
Since you can't shoot at intersections regardless, I think it would be nice if you only ever faced in valid movement directions. That would also allow you to more strategically dodge the final boss by staying in a corner until he shot at you.
I really liked the idea of having the ammo and health be one resource, I think that worked really well, even if it wasn't that obvious to me what that number meant my first two playthroughs or so.