NIN8HALOS'S PROFILE

author=LockeZ

author=kentona
It's not like traditional Zelda games where you can get items permanently to unlock new areas or abilities or whatever. With SMBX there is no real permanence between levels (beyond your own character's powerups, which are lost once you get hit). The only thing that can really mark progress is a WORLD MAP and TRIFORCE PIECES (aka Stars).

This is actually not true, I'm pretty sure! You remember those colored blocks in Super Mario World that are just dotted outlines until you hit a giant button somewhere in the world? You can use these to give Link access to different tools based on his progress. Kill a boss and hit a giant green button, making green treasure boxes appear in each level, which all contain boomerangs; boomerangs can't be obtained any other way. If the player only has Link, it's not hard to design puzzles that can't be solved without specific tools (or possibly with any of a few possible tools)

You'd need to decide which powerups you want to limit this way, and which other powerups you want to never appear at all. And then probably coordinate an order for the stages that actually give these new tools as rewards to be completed in (it would be okay if some could be done earlier than needed, but not okay if you needed powerups you couldn't possibly have yet).