awesomesauce
Well I have been playing it for a few days now and I just got to rank 31 so I figure it's time for a review.
The good:
-I like the upgrade system and specific targeting options. very awesome.
-Great replayability
The bad:
-Screen gets way too cluttered when you get to the higher levels. It would be nice if the turrets were a little smaller (just so the bloons and towers can't overlap)
-Major slowdown [at least on my laptop] at levels 70+
-The fast forward does almost nothing. I'd suggest increasing it to at least 3x so people can advance quickly
-I don't like not being able to access those bonus features. How about making them available at ranks 32+?
-There really should be more free tracks.
Tips:
-It's definitely possible to get to rank 31 without paying for it. The later levels on hard have a RBE of 10k+
-a few maximum-upgraded mortar towers in range of one of those booster towers are awesome.
-on medium and hard difficulties those money farms are very handy. invest as much as you can spare into them as soon as possible (after you unlock them).
In conclusion i'd like to say that this is one of the best TD games i've every played. I'll definitely come back for more every once in a while.