What you fail to notice is that game was sponsered by LucasArts so all the units in it are canon. You cannot call these units uncanon because they were not in the movie or books. LucasArts said they are and since they have the people that decide if things are canon. You can take it out. Fine but you cannot call it not canon.
Actually there are several layers of canon. I didn't make this up and pull it out of thin air.
#1: Movies: they trump everything and the reason is so there is flexibility for Lucas to put on screen what he wants. Period.
#2: Expanded Universe Novels: they are the flesh that fills out the bones that are the movies, however whatever is in them can still be ignored by the movies but are tightly controlled so this is avoided
#3: Expanded Universe Games/Toys etc: they have value and are also regulated by Lucas but a LOT of creative license is given to developers for new content and are basically the skin that rounds out what we know as Star Wars. However they are trumped by both novels and movies and it's not often that game/toy material makes it up to the 2nd or 1st tier of canon but it does happen. Typically when novel writers wish to dip into interesting/compelling characters and bring them to the forefront or when Lucas wishes to move the franchise up a notch. Anyone catch Vader crushing the hospital room in EPIII and how similar it is to Force Unleashed? Force Unleashed is probably the best example as it ties directly to the movies and Lucas is set to make the game tier 1 canon as a result. That's how they are painting it anyway. From this point on you can expect this powerful use of the Force show up in novels and elsewhere as a result.