This game takes place after the first one, and tries to fix some of the issues presented by that game. While it does a fair job with some of them, others are still present. The story is enjoyable, but nothing amazing. And the new approach to level design really did not add much in my opinion. We no longer pick from 3 bots per mission, but are assigned one that is relevant to the story at that point. The level is then designed around a special ability that bot has such as stealth cloak or grapple hook. This is a good idea in theory, but it really was under utilized in the final product. They also decided to create 1 story line instead of 2 in this game. Unlike the first you do not pick to play as autobot or decepticons, but are given story that contains both. The idea was that you would not feel the levels were similar by playing 2 tutorials, 2 end bosses, and so on. However that turns out to be pretty much the case. You will play a stealth level as both sides, you will play a level as a big melee focused brute from both sides. You will play a level as a over powered leader from both sides. While Megatron does feel different from Prime, and the levels have different objectives, they do just feel similar overall to me.
Another issue is performance, mainly the visuals. Compared to the 360 the ps3 game just looks awful. I was amazed at how big of a difference there is. That is not to say the ps3 game looks horrible, just after playing both on the same tv the difference was overly noticeable.
The game is fun, and plays pretty similar to the first one in the series. It has the same loose shooting mechanics, and levels play out similar. If you are not a big transformers fan you may not find this game worth the 60$ price tag though. There are many better shooters, and the multi-player is done much better in other games as well. It has multiple dlc packs out, all are on disc content and cost 10$ and are simply new skins for multi-player.
The game has a enjoyable story, decent mechanics, and big bots blowing stuff up is always a good time. If you are a transformers fan pick it up, if not wait for a price drop.