After the fantastic first game of the Transformers Pick-O-Side series, Revenge of the Fallen falls flat.
The story begins with a young Protoform (You, the CaB), landing on Earth and being picked up by Starscream. Optimus arrives and Starscream faces him while you go join up with Sideways and the others. Once there, Sideways gives you 3 vehicles to choose from (Choose Carefully. You're stuck like this for the rest of the game). Once you have your alt-mode, you go through basics and then go on a journey with the Decepticons to try and revive Megatron and fulfill The Fallen's plan of World Destruction.
This game is pretty short. The day I got it, I finished my college orientation (which ending around noon), and then played and beat this game before we actually went to go see Revenge of the Fallen in theaters the same day. We saw the movie at 4:20. So, in about 4 hours I beat this game. Kinda sad. The plot follows the movie pretty well (except for boss fights, where you kill different Autobots), changing the ending to make the Decepticons win, per usual of the Decepticon side of games. This is really the only thing I liked about this game, being a massive Decepticon fan (All Hail Megatron!).
Gameplay is mission based. To select a mission, you are given a hub where you pick and choose. Many of the missions are tedious and boring. The only really difficult mission is one where you play as Starscream and fly around the ocean for 3 minutes while the other Decepticons revive Megatron. All the while being attacked by jets and boats that do way too much damage for their own good. Otherwise, I never had to retry any missions and I managed to beat them all in a few minutes or less. Boss fights are INCREDIBLY BORING. They are all THE SAME. The boss sits in the middle of the stage and shoots while you shoot back and circle them. After they take so much damage, they run behind a turret, which you need to scan and they get shot by a missile. They then come back out and you repeat. They barely do any damage, too. I had a harder time fighting grunts then any boss in this game. At least the grunts moved.
There is a neat upgrade feature in the game. As you play through, you can unlock weapons and upgrades for the CaB that can strengthen him. As you beat enemies, you also get Energon which can be used to increase your base stats. Since you can't get new vehicle modes, this is really the only way to boost the CaB (the other 'Cons can't use this method of upgrade). It was a nice feature that I think would be strengthened if you could choose your mode at will.
There really isn't anything good about this game. Well, I guess that there are a variety of missions is nice. But, it's a very boring game. It's not even worth the $20 to go get it. Maybe to rent, but I don't know if you can even rent this game anymore. Go get it used and then return it when you're finished if you REALLY are itching to play this game. Unlike the first game, I did not play the Autobot version, but I bet its the same. I wouldn't bother getting this game and if you must get a Transformers game for your DS, get the first one or War for Cybertron.