I really liked DG for a LONG time, even calling it my favorite game for a long time. The problem is that once you get into it enough, it devolves into a puzzle game, where you have to "solve" the level with the single best optimum solution. I have since moved on to more open-level TD titles like Fieldrunners when I get a TD itch.
That being said, DG is amazing, and has a ton of personality.
I don't understand why the developers needs money since their game is on every digital distribution service since years .
Kickstarter is primarily a pre-order service, not an investment funding one, since no contributor gets any points.