Tower-defence games have grown so prevalent even the ones that mix in other genres and rewrite the rules of engagement are cropping up at a dangerous rate.
Downloadable Game of the Week
Anomaly Warzone Earth
For: Xbox 360 (via Xbox Live Arcade), iPad, iPhone/iPod Touch, Android, Windows PC, Mac
From: 11 bit studios
Price: $US10
Anomaly Warzone Earth dials it back with a presentation and control scheme that's pure tower defence, but it flips the script by giving you the keys to the offence - a convoy of tanks, mechs and other vehicles - and tasking you with blasting through an alien defence.
The general rules of tower defence apply, but rather than lay out towers and turrets, you're assembling a convoy line-up and drawing a path for it to follow through and around the streets of Baghdad's and Tokyo's urban battlegrounds.
Vehicle upgrades and repairs replace tower upgrades, a handful of power-ups let you devise temporary defences, and when all else fails, a terrific tactical view interface lets you re-chart your course at any time. Nothing Earth does represents a seismic shift for tower defence, but the change of possession is a welcome twist.
The game's strategic interfaces are polished, the in-game action is visually impressive, and the maps grow considerably elaborate as the multiple campaigns - one traditional and built around a storyline, the others driven more by scores, enemy waves, time limits and survival - progress.
Earth's Xbox 360 version is late out of the gate compared with its counterparts, and the control pad is less ideal than the other versions' touchscreen and mouse controls.
But, along with the Tokyo missions that previously were exclusive to the Mac and PC, the 360 version gets a set of six tactical trials scenarios.
