Arrow keys or WASD to move. 0 to toggle editor mode 1 2 3 4 and 9 to select a tile. e to change the tile to the one you are hovering on. press o to load a level. Note: I fixed Mario's width for coin collecting also I added the feature where you can load a level code.
Note:9 key is for goomba All the credit to @griffpatch except the donut and hard and lava and golden shiny and diamond shiny and screw blocks they were spritersresources.com's ( ͡° ͜ʖ ͡°)