All Items

Terminology

step - A step is larger useful unit of time. I'll most likely make this a second, but will refer to it as a step to differentiate and because certain weapons may alter the passage of time.
frame - A frame is the smallest possible measurable unit of time. This will most likely be 1/24s because 24 is divisible by 2, 4, and 3 so it we can evenly convert between 1/4 step or 1/3 step. This will also vary with time altering items.
loadout - Items can only be equipped/removed at save points. One item will give player a second loadout that they can use to switch on the fly. This also means every item pickup needs to either function as a save station (but not a refill station) or maybe player has limited loadout modification abilities at an item pickup point.
cost - Equipping weapons, armor, boots, etc should cost an amount of energy and ammo. This is an incentive to equip leaner loadouts.

Light beam - This modifier makes the beam reveal tiles on collision (even if beam passes through).
Quantum lock - Similar to ice beam from SM, but instead of releasing on time, releases when a new enemy is frozen. Default is to start at level 2.

Light bomb - Reveals blocks in radius of bomb blast.
Bump bomb - "Jumps" player a given amount. First level is 1.5 blocks and every level adds 1 block.
Dust bomb - Adds dust damage to bomb explosion. This adds additional "bump" but also friendly fire.
Ignition types:
- Instant - detonates bomb 1 frame after placing bomb. The one frame is to give bump direction if player is moving.
- Timed - Bomb detonates after a given number of frames.
- Triggered - Bombs detonate after lifting bomb button.

Slide - Pseudo ball that lets player pass through 1-block gap. If player is not standing on the other side they will revert back to pre-slide space (damage?). (down and jump? slide/ball button?)
Air ball - Ability to morph in the air.
Ally-oop - Press a button (jump? configurable?) to slide or roll into a gap.

"Hot dust" is a small spec of antimatter that explodes on contact. Damage has an area of effect that can be increased with level.

Capacity (ammo) - The amount of dust you can carry is one of the fundamental resources in the game. All dust items increase the total dust capacity. Equipping any dust modifiers decreases the total dust capacity.
Level - Dust level only affects AOE, not damage.
Charged dust - Ability to charge dust. This increases damage, AOE radius, destroys level-2 dust blocks, permanently destroys level-1 dust blocks. This is also cursed, damaging max dust level until the player returns to a save point.

Ledge grab - press a button (direction?) to automatically pull yourself up to a ledge. This effectively increase jump height 2.5 blocks (height of player)
Hi Jump Boots - More granular than other games. Each level will only increase jump height 1 block. However, there's no reason a game can't have "level 4 hi jump boots".
Speed Booster - Grants an additional level of run and makes player do kinetic damage when colliding head on with objects. May also confer this state to the player while jumping.
"Plumber's boots" (temporary name) - Damages enemies when falling on them.
"Plumber's hat" (temporary name) - Damages an enemy when colliding with them from below. (This and Plumber's boots are meant as alternative to the overpowered spin attack)
Lift-off - Functionally similar to SM's shinespark. However, while in lift-off, player's temperature rapidly rises, meaning that the maximum range of lift-off is MUCH shorter than shinespark. Blasting off vertically into the sky means certain death.