The Monster Invasion (Viking Invaders) by Citizen Tree Sdn. Bhd. icon

The Monster Invasion (Viking Invaders) ($0.99) by Citizen Tree Sdn. Bhd. is a new tower defense game for the iPhone where you must defend London from Viking invaders.

I don’t know about you, but I can never get enough of good defense games for iOS. Plants vs. Zombies and The Creeps! are among my favorites in this genre, but I’ll always be open to something new.

The Monster Invasion (Viking Invaders) by Citizen Tree Sdn. Bhd. screenshot

It may be 2011, but the Vikings are back in London trying to take over. Protect London as it is being invaded by monster Vikings wanting to expand their territory. Use the many contraptions you have at your disposal to quickly get rid of these pesky Vikings once and for all.

These creepy monsters remind me of what actual germs look like under a microscope, or maybe an even better example would be those ugly talking mucus creatures from the Mucinex commercials (this is definitely more accurate). Either way, there is something extremely satisfying about being able to spring traps and electrocute the pesky mucus beings.

Watching these little guys fly off your screen or get burned to a crisp before they reach the city is definitely satisfying. You can even drop anvils on them and squish them like the pests they are. Just tap on a trap at the exact moment you need it. There are, of course, minor cool downs on traps, but only a mere two seconds which, for me, never interfered with mass Viking destruction.

The Monster Invasion (Viking Invaders) by Citizen Tree Sdn. Bhd. screenshot

The app has Game Center support with many achievements, leaderboards, and more to come. The tribal-like music and fast-paced tower defense gameplay will keep you on your toes and keep you occupied endlessly. Once you start, even after you fail London and let some Vikings in, you’ll want to start over with every intent to last longer and do better.

This is a nicely done tower defense game for the iPhone, and for only one dollar, you can’t go wrong. Give it a try and let me know what you think.