New things I have spotted.
• Higher frame rate, everything seems smoother.
• The Coin icons on the map have changed, as has the animation of the coins being added to your total. They used to move up in one clump, now they stream one after the other.
• Skywarp can eliminate levels you cant complete.
• Seem to be two new areas you can explore, City and sort of River area.
• New type of enemy, the Piranhacon.
• Some levels have Slow Mo and Speed Up zones, these are activated as you pass through coloured gates.
• The City levels have large, lit up targets that when hit release an energon cube.
• You may notice Soundwave in his Cybertronian streetlight mode in the City.
• A new collection of trophies to achieve.
• You can buy accessories for your bots.
• You can upload success images to Facebook when you complete a level.
• When you attack a gold box in a level with Grimlock, instead of waiting for the box to be destroyed to add the coins to your total they stream one by one as the damage is done. You don't need to destroy the box to get some coins. The box seems to change colour as you deplete the coins it contains.
• There is a Leaderboard icon on the map, don't think that was there before.
• While a bot is being upgraded you can now access the list of characters to see their level or buy accessories while the upgrade takes place. You couldn't see the others before, only the bot being upgraded.
The bots are now divided into Groups, they are:
• Rescue Bots - Optimus Prime, Bumblebee and Heatwave.
• Instruments of Destruction - Soundwave and Soundblaster.
• Target: 2006 - Ultra Magnus, Galvatron and Jazz.
• Pure Warriors - Lockdown, Energon Lockdown and Brawl.
• The Seekeers - Energon Starscream and Thundercraker.
• Energon Fueled - Energon Grimlock, Energon Soundwave, Energon Galvatron and Energon Optimus Prime.
• Variant Versions - Ultimate Megatron, Ultimate Optimus Prime, Ultimate Grimlock and High Octane Bumblebee.
• Leaders - Bludgeon, Sentinal Prime, Grey Slam Grimlock and Dark Megatron.
• Unlocking all characters in a group will add a percentage bonus to your pig/coin score on a level, max bonus seems to be 40%.
• Characters in certain groups have different abilities. Ultimate characters, for example, get their pig and coin score doubled when they complete a level but if they don't complete it they get nothing at all. Energon characters are more powerful but have weaker shields.
That's about everything I have noticed so far.