The developers wanted to release the game for Nintendo WiiWare, however due to Nintendo's 40 megabyte cap for WiiWare titles, they weren't able to reduce the game's size to fit. Content which would've had to be reduced was the music, to achieve the intended file size, however, the developers felt the tracks should be kept as they helped to provide an impact to the game.

The developers instead tried to find a publisher who would release a retail Wii version of the game, but the three biggest publishers said, "there's no money in third-party retail (on the Wii)".
Contributed by KnowledgeBase
During the cutscene in which Dr. Fetus is being built, a shadow of what appears to be GLaDOS from the Portal series can be seen in the background.
Contributed by Boyobmas
Edmund McMillen of Team Meat had to sell most of his games and DVDs, including an out-of-print Sleepaway Camp box set, in order to fund the development of Super Meat Boy.
Each of the intros to the stages are references to other classic video games. These are:
Teh Internets - Bubble Bobble
The Forest - Street Fighter II
The Hospital - Castlevania
The Salt Factory - The Adventures of Lolo
Hell - Ninja Gaiden
The Rapture - Megaman 2
The End - Pokemon
The Cotton Alley - Ghosts and Goblins
Contributed by gamemaster1991
In the PC and Mac versions of Super Meat Boy, if you type "petaphile" on the character selection screen of a level, you will be able to play as Tofu Boy. Tofu Boy can not run and can only barely jump, making him the worst character in the game. Tofu Boy is a joke, referencing PETA's Flash game parody of Super Meat Boy.
Contributed by Des
Meat Boy from Super Meat Boy is not in fact a chunk of meat. He is a "boy without skin," as said by the game's creators, Team Meat.
Contributed by jfed8888