Completely offtopic, I know, but imo you should rethink about offering a potential highly frustrating experience without checkpoints / savegames or instant replay. (Check out Super Meat Boy and VVVVVV)

Okay thanks I think I will just go with a flat SM3.0 requirement and compiler then.

Regarding the difficulty: I really like difficult games and I think modern games are way too easy. The market is flooded with easy and casual and puzzle based platformers, so that's why my game is nothing like that, too. I have only two levels with checkpoints and those are long levels. Most of the other maps can be completed in 90 seconds when you speedrun them which is a little too short for checkpoints. Trying to make a level longer is surprisingly hard because you have to come up with new platform patterns and obstacles all the time so I've decided to keep them rather short and without checkpoints.
Btw. high difficulty does not mean a frustrating experience, actually it can be more satisfying this way to complete a level. Although I make the levels pretty hard I always try to keep them fair which means that the player is always able to see what is about to kill him.

I definitely understand where superku is coming from. for instance, call of duty single player is easy, and it is complete crap, but me and some friends spent hours on the veteran spec ops because it actually is quite difficult. Granted the genre is drasticly different but I think the same theory should still apply

High difficulty does not necessarily mean frustrating experience. I mean potential frustrating experience. Because every player is different. VVVVVV and Super Meat Boy are extremely difficult, same for Super Hexagon. But they offer checkpoints and / or instant replay for the sake of flow.

The programmer of SMB explains their system in "Indie Game: The Movie" and I think it´s a real good approach. In the german Making Games magazine issue 3/12 there was a nice explanation of it, too. It boils down to "frustration is removed by shifting from losing lives and replying a whole chapter to having unlimited retries in rapid succession and keeping the level goal in sight"
I think the last part of this conclusion is most important.

Just some thoughts of a grumpy old man, don´t take me too seriously.

...or you could give option to the player "to cheat or not to cheat"... or to buy online some expensive packs