there is some bug for me - the game runns very jerkily when it has focus, if i click outside the game it runs smooth - but then of course i cant control it :)
fix that and it would be a lot more fun for me....
i really like the game but yea its a bit too hard. Starting with the crossbow and the little girl seems easiest. Selling expensive guns you seem to loose far too much money, and the levels do seem to get far too hard too quickly.
Just a little rebalancing and it would be great.