This is a guide for the category "Any% with cheats". This category allows internal cheats only. If you find a faster alternative to this route, feel free to suggest it within the forums. Suggested routes for Any% without cheats, would be appreciated also.

0. Start a new save file.
1. Play the introduction level. No skips have been discovered here yet.
2. Play Shop Till You Drop. You may use the Out of Bounds glitch discovered by Isaq21. You can see a video of the glitch being performed at [1], starting from around 1:07. This will allow you to complete the level in around 2 minutes, saving 2 minutes and a bit.
3. Once you're in the hub, head to the right and then forwards to the pipe positioned in front of the bulldozer. Press A to enter the level select screen. Try not to pick up any XS items at this time, as you may lose a few seconds.
4. Hold C, Z and B, and then start holding Up. Press "No" to any prompt to return the hub. Stop holding the buttons when your pile reaches 3200ft.
5. Start "Keep on Piling" and complete the level. This is to get the B "boost". The final level is impossible, to my knowledge, without it.
6. Enter the pipe in the hub again, avoiding XS items.
7. Hold C, Z and B again, and begin pressing right to advance to the next tier until you reach the final tier. Navigate to the last tier, then hold C, Z, B and Up until you have accumulated enough stuff to enter the last level.
8. Enter the last level and finish it.

Let me know if I've missed out anything.

Resources [1]