At the title screen, select "Start Game" and immediately press the tilde button (~) on the screen with all the items of the game and their descriptions. Finally, when the screen with the lamp shows up, press the backspace button. Once done, activate the following cheats by pressing the corresponding keys:
CHEAT FUNCTION - KEY Automatically complete the current level you are on, and progress to the next level. - Press keypad + Automatically kill yourself. - Press keyboard Tab Increase apples by 5. - Press keyboard a Increase gems by 5. - Press keyboard g Turn on/off free movement (allow your character to "float" to any position on screen; enemies will try to attack you, but you won't take damage). - Press keyboard m Turn on/off invincibility (take no damage). - Press keyboard h Turn on/off objects (if a genie or heart, for example, is hidden behind the artwork, this code will bring it to the foreground so you can see it). - Press keyboard u Warp to any level of the game. The letter a corresponds to the first level of the game and m corresponds to the last. - Press keyboard 1, then any letter from a to m.
To defeat Jaffar in the final level avoid going near him and try not to get pulled by him. Hit him with apples at intervals. After killing him he will become a snake. Hit the snake with apples until it is defeated.
Toward the end of the desert level, when collecting the gems and apples from jumping onto the bricks, retreat a couple steps back to the pillar which will take you up to the merchant. If you have the gems, you will earn extra lives.