Defen-G Astro

Tower defence games are ten a penny on the App Store. Whatever your poison, there's probably one of these stripped down strategy games out there that's perfect for you.

All of them follow the same basic template. Here are your units, here's the money you have to spend - now stop this horde of rampaging goons from reaching your tower and pulling down your expertly crafted masonry.

Every once in a while you get a game that plays around with the fundamentals of the genre. Some of these experiments fail miserably, but others manage to craft something a bit special.

Defen-G Astro is one of those norm breakers. It picks up the tower defence genre, gives it a shake around, and comes up with something familiar yet unique.

The first thing you'll notice is that it's a side-on tower defence game, eschewing the usual-top down view for a more action-orientated perspective. The game is presented in stark silhouette, with cute cartoon graphics and some impressive character design.

You place your units - brave knights, archers, bombs, and fish tossing whales - and then let the enemy waves sally forth. Each creature you send back to its maker earns you more cash, which you can spend on upgrading and strengthening your army.

Since Defen-G Astro is 2D, you rarely have to scroll through the battlefield to make sure your far-flung towers haven't been overrun. The action is fast, furious, and focused. Luckily, you have at your disposal a limited number of healing and shielding potions, which you can use to buff single units.

The globular attackers come at your rotund defenders in waves, throwing spears, hacking with axes, and generally making a nuisance of themselves. The key to your survival is your ability to stack your units in piles of three.

Stacking lets you triple your offensive force while only taking up a single space on the playing field. Some units can't be stacked and others can only be stacked if unimpeded, so learning which unit can do what is an important part of the game.

While Defen-G Astro is action-packed, it doesn't quite get the balance right between the different units you can use. Archers are seriously overpowered, especially in the early part of the game, and you'll end up using your other units as nothing more than meat shields.

Once you're deeper into the game, and your army is full of Minotaurs and cannons, things settle down and the balance improves, but it's very very rare in the first few levels to feel like your tower is any danger at all.

Defen-G Astro is a solid and charming tower defence game. It might not have the depth of some other examples, but it's worth playing for its presentation and its unusual 2D twist on the genre.