The basics behind Invader Attack
are easy, but it's not without its subtle complexities. In addition to the aforementioned "ships colliding with other ships" mechanic, you also have to deal with inertia. Unlike the tank in Space Invaders
, your tank cannot stop on a dime. If you're going in one direction and suddenly need to drop into reverse, there's no guarantee you'll dodge out of the way.
Your tank's momentum is also affected by shots or anything else you might happen to run into during your mission. It's such a simple idea, but adds loads of strategy to an already strategy-filled game. It helps elevate a "simple shooter" to a fairly hardcore one.
Blasting enemies produces power-ups, most of which will help you take on waves. There are extra lives, health power-ups and rate of fire increases. The variety is decent, though a few new gun types or shot patterns would have been welcome. There are also a number of power-downs that can really throw things out of whack.
Invader Attack is a simple game, but still fun. At $9, it's a great pick-up for fans of shooters, particularly fans looking for something more strategy-minded.