not optimized for Android which makes u lag so hard it becomes unplayable.if it crashes & u try to continue the lvl u were on it restarts the lvl completely but leaves u at low health from prior waves. Example killed boss on stage 2 with 150 health left, crashed because of stupid over the top boss death animations, reopen, continue lvl when it asks if I want to, I'm at 150hp like I was when I killed him but the boss now has all 6 health bars back, so fair. lag so bad can't dodge on any level.