Invicibility:
As Rick O' Connell, successfully get to Ahm Shere. Then go to the middle of the place. Puause the game and press Up, Down, Left, R1, R3, Triangle. YOu'll return to the level and your energy bar should raise and then remain there.
Unless you like killing yourself:
When playing as Imhotep and find the curse of the death, don't bother wasting life using the curse of death on bosses, as they are not affect by the curse of death.
Walk on swamp glitch:
When playing as Imhotep, find the swampy place in the jungle. You'll need to have raised the block in the swamp. Jump onto it with Imhotep, and then use the Apis Spell. Run off the block and you'll be able to walk on the swamp for a short amount of time. Don't try this if you are running low on energy. Also do not use curse of death.
Imhotep Hint:
Don't try to use the curse of death on the bosses as it has no effect on them and you'll end up wasting life.