The main new feature is the ability to share energy between robots: in single player mode you press a button and the current robot starts sending energy to his twin, who receives it automatically. In multiplayer mode both players need to press the button to agree on the energy exchange. Thanks a lot to +Andrew Perry for suggesting this "helping" mechanic!
Besides the new feature, this update includes some extra help in the form of tips: Looking at analytics I've found that the 2nd most common reason why players die is... jumping! Since run, jump and other actions consume energy you may die while doing these common actions. Now whenever you die like this for the 1st time, a panel slides in showing a related tip; this panel is shown only once, so it won't be like those constant reminders appearing again and again. Also, the gameover screen now includes some advice too.
I've also included a screen showing "demo is over" when you finish the first 3 levels, for clarity sake.
And finally, now the single player mode accepts input from any controller you have connected; it only read input from controller number 1 before, so if you have a keyboard connected to your ouya (which is recognized as controller #1) you were not able to play the game with your gamepad on #2. This should be fixed now.
I'm currently testing all these new features so the update should go live in a matter of days!