Great TD!
To all the little whiners who thought this was too hard, "Go find your grandma's TD and get a little practice in. This is not for those who don't know how to play a TD."
I thought this was well done, takes a little while to figure out the best placement to defeat the level, but you feel really accomplished when you get it. The cannons are just a little too slow, but I haven't gotten one of those to level 10 yet. Survival is great and feels almost impossible to defeat right before the 15 minute mark.
Overall, excellent and addicting, spent way too much time trying to get the achievements, but it is the best way to work your way through it.