Well worth the money!
The game itself has a large handful of levels which all require a new strategy for each whether it be the towers you choose to purchase or upgrade and/or the varying enemy types which also look cute and cuddly that you have to cope with as they tend to have their own strengths and weaknesses.
Also there are special levels that upon completion, whether it be perfect completion or with some loses, your character earns special upgrades that I have found greatly help the player, too bad I'm not gonna reveal them though!
Well, continuing on, I can say that this game has been worth every penny. My brother and whoever else wants to play including myself (duh) always end up playing 2 player and share strategies and laughs while having fun at the same time despite wins or loses.
If you like tower defense games then you should buy this, now.
Can you get all the rainbows?