-The objective marker isn't a bad addition but it can't be at last building. It can be a bit disorienting. Being in every consecutive building could be an upgrade. Not only that but there are many other ways that you can guide the player where to go like: different light colors, signs, new enemies on the way, yellow paint lol and other many ways :).
-The healing takes too long, especially when you fight enemies with shotguns(at least get full healed during each break between waves).
-Getting rid of the bullets inside the gun while reloading is just a no no.
-And be more careful with the collisions.In the first level, you can jump on the second building only if you get on top of one of the little pillars, which is a bit annoying.
PS: Just know I discovered the dash mechanic and it's very broken. I think just a simple wall run mechanic would have been more convenient.