on normal, hard mode is that supposed to be harder than insane mode because i thought hard mode was waaaay harder than insane! anyways 5/5! with all acheivments
the easy way is on the first round just do nothing but headshots, same with the 2nd and the 3rd and the 4th and the 5th round and dont buy anything till the 6th round, buy the take no damage and then if you have enough buy more damage and repeat to get all upgrades.
One thing, it gets pretty easy when you get double shot and quick shot! :(
4/5
a good way of doing the controls is move with arrow keys and shoot with mouse, that would be easier. But great game anyway, you still get that arcade feel to it!