Game freezes if I select Special Attack during a fight. Browser and Flash plugin are still operational (right-click menu for Flash, for example), but the game just stops completely.
Great game. Only suggestion is to enlarge the hit boxes. Popup menus to select method of killing are really difficult to hit in a timely fashion, and certain encounters are very difficult because you waste attempts trying to click a tiny hit box in a very short amount of time (ie jetpack vs ninja).
Difficulty is too high in the beginning. Grinding is a requirement and you have to be impervious to failing over and over and over again to that one wave that is immune to your units.
I liked it right up until the part I was mysteriously sent back to the title screen. This happened in consecutive playthroughs at the Cafe sign screen. 1 star for broken game, but if it's fixed I'll come back and give a favorable rating.
@varix.: I mean, it's a couple years old at this point, but it is a quadcore cpu with 4gb of ram and a 512mb video card. I think it can handle a flash game, seems maybe a problem with the game itself. I don't know, memory leak or something?