What button combination is used to skip through the game so quickly? I tried every key on my keyboard with no success.
For Any%, hold the shift button while pressing "Play Frog Fractions!" to show the upgrade menu before eating any bugs. From here, get the upgrades necessary to beat the game by holding shift and clicking them. When you start going into space, do not move. When you are in the tunnels, I suggest making notes as you watch the WR video to quickly make your way through them. For DDR, play it correctly for 57 sec, then stop. This will cause the end of DDR to come faster. After this, just hold the down arrow key (or S) while you wait for the cutscenes to finish. This is the Frog Fractions Any% route for the main game, not the DLC btw.
You can also check out the guide by Scrublord on the 3 major skips in the game
Again, the guide is for the main game, you can try and find one for the DLC