Blast Radius is an interesting take on the growing Tap Defence genre and the blast mechanic and upgrade system saves it from being just another game about tapping to survive. Though it won't pick up any prizes for style, it's still worth a play through and can get quite addictive once you get into the whole upgrade mechanic.

If you just want a bit of fun, it's certainly very much worth the $0.99 asking price. The gameplay is good fun and the upgrades and economy sides of the game add something new to this genre, and it works very well. But, the more competitive players may get a little frustrated by the in-app purchases. It seems a subject that iOS game developers still haven't quite got their heads completely around, yet.

A decent defense title that is saved from mediocrity thanks to a rather unique gameplay mechanic.