Not bad dude not bad, Bravo, P.S I love having to upgrade! I know that in the start its rusty and for the newbies, make sure you upgrade your allies or else you'll die.
Here's how you defeat the giant turtle boss thingy.When the overweight guy climbs out and shows himself slash him,in the meantime when he dosent show himself kill the flying soldiers and throw them at the turtle shell so you can at least a little damage.
The good thing about snipers is that you can place them in non-stratigec spots and they still do fine!Example:Your in the intermeditate island map and theirs the little broken ship you can place a sniper there!