I may be more forgiving than a lot of gamers, but even I find it challenging to not be somewhat disappointed with this.
Fundamentally, this is different than the Xbox 360 and PS3 versions. This is an arcade-like, beat 'em up game. There are different attack combos to unleash, including a special attack for each character, and quick time events to finish off boss characters. I find the gameplay to be okay, maybe a bit repetitive at times, but it's adequate and can be even entertaining. However, the fact that the next-gen versions were an improvement on the first one, a free-roaming, epic adventure in realistic settings, really annoys me quite a bit. You can't even transform at will in most levels (and this is a TRANSFORMERS game).
Considerably worse than that, though, is the story. You cannot choose sides, and instead alternate between Autobot and Decepticon levels in the campaign, taking away any element of choice. What if you wanted to destroy Earth instead of protect it? You can do that with the next-gen versions, but not here. The human characters make no appearance in the entire game and only do a bit of talking at the very end. Also, the Transformer cast has been stripped down immensely-three playable characters for each faction.
Worst of all, the game is very short. The single player mode consists of one fifteen mission campaign, which takes way less time than it might sound. I finished it three times in about 10 hours. The 2-player mode doesn't help much, since it only throws you and a friend in a small stage and sends endless hordes of enemies at you. Gets boring after a little while.
I believe that the PS2 version of Transformers: Revenge of the Fallen could have been better as it is, but the effort to make it wasn't too high at all. In fact, this letdown is what has made me try to get an Xbox 360. Only gamers staunchly loyal to Transformers are likely to have any real fun with this game, and even they may be disappointed. Get the Xbox 360 or PS3 versions if at all possible, and if you seriously want to try this rent it first.