There are a few minor annoyances...
Only right Shift and Ctrl work for activating special/bombs... With Space and the Mouse/Arrow Keys being used for other things, this is INCREDIBLY awkward to use. Unless maybe you are left handed...
Overall gameplay was relatively fun, the specials seemed ineffective and the bombs would be better if they could be tossed further into the field.
Music was alright, but it got annoying during one level. The "story" was pretty cursory, it is not integrated into the gameplay at all.
Requirements for "perfect" level score isn't described.