Keep an eye on the energy meter which is the bar located at the top of the screen at all times. The energy meter depletes whenever you make a move and when it runs out Jumpster will become immobile forcing you to put the game down and wait for it to fully or partially recharge. You can of course if you don't want to wait top off the energy by making an in-app purchase.
Place Jumpster in water whenever possible, if you leave Jumpster on a hard surface for too long he will die. A good strategy therefore is to always seek to send him into a body of water or water bubble.