SEGA Genesis Classics

Once you've loaded the game up, click on 'Options'. From here, highlight the Shuriken option and move it down to 0 - This will now prevent you from making any mistakes. Then scroll down to the music option and press (B) on the following songs in this in this order - He Runs, Japonesque, Shinobi Walk, Sakura and Getfu. Congratulations, you're now invincible! Once this is all done, leave the options menu and start the game.

Once the first level 'Round 1: Seed's Resurrection' has loaded, just hold down to fast forward and make your way through it. There will be a few enemies (mainly mini/bosses) you'll need to kill - just spam (B) - but other than that, you can complete the first level in about 3-5 minutes.