As is typical for this style of game there are different types of towers, with a rich system of upgrades. You can also place traps and use medicines to help defeat the ravening hoard. In all there are 32 levels to complete, with a good learning curve, such that you are required to think more strategically the further into the game you get.
It's clear that a lot of thought has gone into the design and playing style of the game. For example, the enemies behave and move in an unpredictable way, which means every time you play a level there are subtle differences. Other highlights include the in-game tutorial system, the easy-on-the-eye graphics, and the fact that the game is available for both Windows Phone 7.5 and Windows Phone 8 devices.
What's not immediately obvious is that the bacteria and viruses that you face in the game (and other curiosities) are based on the real thing (at least in name) and you can read more about them via in-game descriptions. The idea of using the human body and immune system as the template for a Tower Defence game is not something we've seen before, but it is a clever concept, and one that works much better than some of the more convoluted implementations we've seen.
Windows Phone Store description:
It's not only a game - it's real life. Challenge yourself in brand new biological-strategy game.
John needs your help! He's the one with bad luck - all the diseases are constantly attacking him.
Take control over his immune system and kill hordes of sneaky bacteria. Trust me, it's not so easy. You have to think, choose the best strategy and react right on time.
Vein Rush can be downloaded from the Windows Phone Store. A free trial is available with the full game costing £0.79 / €0.99 / $0.99.