Yeah, Sunsoft is the hardest rating on the Megadrive version of Lemmings, which is where I got the name from. Sunsoft is the highest rating I use, which is just harder than Mayhem. And the cheat code to access the even-numbered levels is 'SKIPLEVELS', then go to the level before the one you want to access, in this case level 5, and press '5' on the numberpad, (it's the same key regardless of which level you want to acces), and the level will exit immediately and say you've saved 100%.