Just downloaded the trial version. Heres my thoughts.
Pros:
HD wall textures look nice
The fist and assault rifle weapon in hand sprites looked pretty good as well.
Smooth 60fps (The game did feel a lot smoother.)
Solid controls (I was able to beat the first level on total carnage the first time through, and didn't feel like I was stumbling with the controls. Aim assist and the crosshairs were turned off as well)
Cons:
Pfhor Fighter and Drone sprites look rather different from the original and kind of ugly.
The pistol, weapon in hand, doesn't look like its positioned right.
Even on an HDTV, with enlarged font, I still found it kind of hard to read the terminal text.
Unfortunately, the trial version didn't include multiplayer or the new survival mode. Overall, Freeverse did a pretty good job of porting it to the X360, however I'm probably not going to buy it.