It is possible to edit the control mapping, although not in-game. In order to do this you need to edit the file buttonmap.cfg. If the game is installed on Steam, it should be located under:
Program File > Steam > steamapps > common > super meat boy >buttonmap.cfg
The file will look like this:
keyboard
{
up="up";
down="down";
left="left";
right="right";
jump="space";
special="shift";
}
gamepad
{
jump="1";
special="3";
useanalog="true";
}
Simply edit the corresponding line to change the key bindings. For example:
keyboard
{
up="up";
down="down";
left="left";
right="right";
jump="z";
special="x";
}
gamepad
{
jump="1";
special="3";
useanalog="true";
}