Lost Levels has recently talked about an interesting discovery: a working proto of Happy Camper, an unreleased platform / action game that was in development by Color Dreams for the NES. It seems that the game was too hard to play.. and after some changes in the difficulty level options, it was already too late to release the title with a decent economic margin. You can check the original story at Lost Levels for more infos and screens!
Thanks to NGD for the additional screenshots!
More infos: NGD & Happy Camper Interview