great concept love the idea but i do agree instead of stamina go with health like say you start with two hearts but you upgrade to get more and you can still keep the idea where you hit 20 enemies to gain more stamina/health. but over all great quallity game
as i am writing this i got my combo meter running on classic mode i only have four buzz saws to mines two trampolines and three sentinals, and 5 turrets. im still going because of one turtle stuck between the trampolines and the sentinals.but final combo 10 min later is 4251.
another glitch i found was getting 25 shots in a single clip for the shotty very overpowered but it works. while using the uzi press spacebar really fast while reloading to get the glitch described