2464529662 points on medium difficulty. Got to wave 489 with 3662 kills. Don't know if it counted the black hole kills (I don't think it does). Fun game. Got to a point where I just walked away and it did the next hundred waves on its own.
My game is stuck on a glitch on the traveling screen going between towns. I've run into a glitch a couple of times where if I run into buccaneer's before the screen has reset after a battle, it will let me skip the battle by pressing go again, but now I am trapped at a town, continuously traveling with no way to ever stop. A feature that lets you change destinations while traveling would be nice.
This game was a lot of fun. Finally got the tank and golden gun, bought 15 or so nukes and a chest bomb and let 'er go. New Record: 3464934. Have all achievements too.
This game is definitely one of the best tower defense games out there. I think that you should be able to combine gems at the towers though, it would make the game a little better.