AFAIK its only an XBLA community game.

It differs from soldat in a few major ways:

Running on all sides of the terrain - Yeah, you run on the walls, celings and floors. Takes a while to get used to, but its fun once you do.

No jetpack - closest to the pack in ZP2k9 is the "Bee Suit". More on that later.

Power Up Suits - Randomly scattered suits give you various bonus powers. Some examples are:
Cat Suit - Jump higher and run faster
Bee Suit - Flying
Bat Suit - Health leach and Invisible while upside down
Derka Suit - Big explosion upon death
Hedgehog Suit - Double Damage
Skunk Suit - Immune to poison and emit poison

Weapons are also scattered randomly and vary from pistols, swords, rifles, shrink rays and more.

Awesome fun.