problems that i faced when playing the game:
1: no idea where the xp orbs are when i kill something and get away from them, any kind of arrow would be of great help
2: twice i got stuck on wave 6 where the enemies are not coming, i think it's the green guys
3: visual bugs where the xp does not thouchs me and becomes a ray of light
but it's really fun act like a boss and kill every thing with a mine or get on the enemy cluster shoting and avoid getting hit