Good game
Took me 2 hours to get all the achievements because the "Played for 2 hours" Achievement was the only one left to obtain within less than 2 hours... in fact all I did after getting everything was wait for that one to pop up.
My high score in the Endless Defense was beating 20 waves with over 200k of score. I could have definitely gone for more, I hadn't gotten hit yet or anything. Plus only wasted less than half my clip for each wave. Just got dull after a while.
It's a good game... would need more levels, perks, and missions. But a fun game to pass the time nonetheless.