I'm pretty big on tower defense games.
These are some random notes which I'm putting up to get them out of my hair.
Protector IV.V ∞
Protector IV.V is really great. I'll write my thoughts in a separate post.
Bloons 5 ∞
Right now i've been playing Bloons 5.
It's pretty good, but all plays are either too easy or too hard. There's no actual struggle.
Levelling units is nicely done, and the abilities are varied and interesting. The different daily maps are usually pretty good.
A ninjakiwi.com account is needed to save your games and get some extras. I recommend it.
Starland Multiplayer TD ∞
Some gameplay screenshots, showing some ideas for unit placement which I was either playing with or had seen in action.