CLICK GREEN FLAG TWICE!!! arrow keys to move, red kills you, platforms move, the border doesn't kill you, hold x to delete blocks, press the button to close the window, q and e to make portals and r to delete them (one second cool down to go through) down to crouch. wasd and space work too.
noted bugs: you get pulled up through pink blocks, you can climb the border, you can interact with the blocks in the menu, when you click the button the blocks delete themselves, you can get stuck on one level and not be able to jump or fall (click flag to unstuck, only happens during startup). i am working on it. tell me others you notice please -j