Simple and short, really no lasting value. 6 units overall, 2 melee, 2 ranged, healer and slower. Place them, upgrade each ones health and attack 5 times, and use the three abilities of your main guy, the one you need to protect. That is it really. There are some resurect and teleport abilities, but they seem pretty useless as I did not need to use them once.
Even counting the "arena" which is the same map 5 times, increasing in difficulty each time, there appears to be only 9 maps overall, even though it seems to suggest at the end that there is more, maybe unfinished? Each map will take you 5-10 mins tops. There is a high score feature that you can upload and see your scores against other players, but it basically asks you to register to do this and I felt uncomfortable putting this in so never completed it.
Feels a lot like a phone or tablet game, even though I can play tower defense games on my phone that keep me busy for weeks, some of them free, all of them cost less than half as much as this.
There is no way in the world you can justify spending the full price on this game, or even on sale. Should have been a little side game that came as part of the package when buying the Two Worlds 2 RPG.