In this hack, the D-Pad does nothing. Control Mario using the A key to jump and the B key to speed up. It can be thought of a cheeky test of the maxim that the easiest way to beat a Super Mario Bros. stage involves running to the right without stopping. The levels are largely unmodified versions of Super Mario Bros. levels. Unlike its inspiration, you often need to slow Mario down or speed him up to get past obstacles and to claim purchase on vital platforms. Like its inspiration, running into solid objects can be useful for earning a temporary break in the action.
I've ordered these levels based on aesthetics and their overall difficulty.
And, as in Normal Mario Bros., you only need 10 coins for a 1UP. This means, among other things, that hitting the ?-blocks in mid-run is essential to maximising your lives.