https://www.twitch.tv/videos/1117779770?t=02h16m17s

Puh, that game is really hard! I don't manage to survive more than 40 enemies and so I'm far away from getting enough orbs for testing the revive function. 

I would have prefered arrow-keys and W/S to move. In regards of the amount of enemies the space bar is really difficult. Specially because the enemies are coming in really fast and sometimes it just feels unfair. The amount of orbs required for revive should also be less. 

Besides that you also should always add audio to your games. If you don't have any I would recommend to keep an eye on humblebundle. It is the cheapest way I know.