The curious thing is, I found it more absorbing on a personal level than the average tower-defense game, and I’m not sure why. Usually with TD games I sit back comfortably, enjoying god mode, and not really worrying too much if I lose and have to replay a level. Here, though, I was more invested in my little mining colony. In the final level where the pirates come in thick and fast and my colony gets completely massacred, I had to give up after a couple of unsuccessful tries — it just felt too much like one of those really grim episodes of Babylon 5 where everyone is dying left and right and I cannot make it stop.
But, er, you may not have that same problem! And it’s fun, though not remotely IF-like.