I have played the dev build approximately for one hour and was able to get 8 level max. Too hard. Was not able to buy drone. Hard to get health regeneration. After boss the enemies moves extremely fast and all of them comes simultaneously. Looks like boss is not the hardest part but next levels are. Player moves some time after dead, so player can be dead, pickup life and play further. Some enemy death animation restarting if continiously shooted.
Summary - cool game, need to be improved.