This game could be great, but:
* Poor Xen level design
* Too many invisible walls in Xen
* Poor texture (or whatever it is) so you stuck or slide and can't jump and move, especially in the Xen world
* Poor localization
* Wrong tips for long jump in Xen
* Wrong achivements description
* Some achivements are broken
* Many game crashes
* Many UI glitches, like you can't see your HP sometimes or can't see menu.

This game could be great, but: * Poor Xen level design * Too many invisible walls in Xen * Poor texture (or whatever it is) so you stuck or slide and can't jump and move, especially in the Xen world * Poor localization * Wrong tips for long jump in Xen * Wrong achivements description * Some achivements are broken * Many game crashes * Many UI glitches, like you can't see your HP sometimes or can't see menu.