No, my cat did not walk across my keyboard while I was typing the title, SDGPSnK is one of the craziest names of all time and inspires me to create a GOTD Hall of Fame for best game names.
SDGPSnK (from now on called "it" because I'm tired) is a combo platform/horz shooter with a cutesy take on the Gundam world and a lot of gameplay.
You're just a dude with a gun and a jetpack. The first button shoots and the second button jumps. In fact, you can double and re-jump and kind of float all over the place with your jetpack. You can also duck, but you can't shoot while ducked/crouched (so you may as well cry while you're down there like a chicken).
There are lots of power-ups, but you have to play for a while to collect them. Bigger guns, independently shooting satellites, energy, flamethrowers and other fun stuff add to the destruction. And make sure to grab that damned shield. And yes, the energy is for your energy bar, if it gets depleted you lose a life (although some things can kill you all at once despite your gauge).
The graphics are fun, light. nice and interesting. They are a cartoony and varied version of the Gundam universe. Through the many levels, the backgrounds change a lot - space, grassy countryside, caves and cityscapes are all in the mix. Another nice graphical feature is the quasi-parallax scrolling and action that takes place in the background. There are enemies approaching that you can see roaming around back there, but until they reach the foreground, you can't shoot them.
It's a fun and straight-forward game that'll satisfy your itchy trigger finger (and itchy jumping-packitis). The game has many levels and the variations keep it playable throughout.