A few months ago I stumbled upon some retro platforming game by finding its soundtrack on Bandcamp and it's called Crystal Towers 2:
Basically it's a mix between Mario, Sonic (Sonic-like graphics and music, but minus the speed), Zelda (items/spells/energy upgrades/RPG elements) and Mega Man. The graphics are simple because the author tried to mimic the Super Nintendo and Sega Genesis. Even the music sounds kinda like some Sega stuff. What I like in particular is that you can almost go beat stages in any order and also the fact there are multiple objectives/achievements per stage to do to unlock others. Also I like the music (especially the boss).
The demo is free but the full game costs $5. However I don't recommend buying it until you completed about 10% of it, because it gets pretty hard sometimes and the free version is already incredibly long. I think there are 33 stages with about 8 objectives each, so technically 264 stages and 8 bosses, along with many items/magics/power ups to find
You can download it here:
http://www.clickteam.info/davidn/ct2/download.phpA calc clone of this would actually be great too actually, but due to the ridiculously insanely long game lenght, it would be impossible to make a port of the entire game. I think it would have to be a brand new game based on this one or maybe the first Crystal Towers from 2004:
http://wired.st-and.ac.uk/~wong/crystaltowers.zipAlso the game crashes from time to time, but so far it only seems to happen after you die like 200 times without restarting the game.