EDIT: It has to be a trophy that uses power. Place the trophy in inventory, then refund to subtract the power amount of the trophy twice. This also works with regular items, but trophies are permanent so you can keep doing subracting for free.
there's a glitch where you can have item combinations that exceed the power limit.
You don't need any power boosters at all just a trophy. Equip the trophy, then put it in slot, then place the trophy back in the shelf. If you do it then the power meter should subtract by that amount twice. Then you can keep doing it and reach negative power, all without buying a single power booster.
Rolling is faster than running. If you roll then immediately jump, you gain some extra momentum.
You don't have to cling to the wall to walljump, you just have to be "touching" the wall, then press space. Saves lots of time.
Also, when you have to run then turn the other way to jump, rolling cancels the skid in your previous run direction. Top that with the roll jump that will save a few seconds of time if used repeatedly
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