I waited too long to play this game...
I recently picked this game up and have since beaten it three times. The presentation is amazing. Great graphics, sound (original voice actors and good music), and gameplay. It is high speed robot crushing action sprinkled with a good story. The combo system is fairly simple by todays standards but I never got tired of it. I think I prefer the simplicity.
The one thing that I had any issue with was the upgrade system. I didn't understand what I was doing until late in the game but it really didn't matter on the default difficulty. On the harder difficulties it becomes very important to upgrade your S and SS weapons to suit your playstyle (and sometimes a unique situation). It all eventually became very clear and I then enjoyed the loot/upgrade system.
This game has turned me into a bit of a Transformers fan. I watched a few episodes of the old cartoon (kind of hard to get into) and have purchased two of the IDW comic book collections. I even bought an Optimus Prime figure.
I recommend you try this game out as it is now one of my favorite games.