Items!

Without items our lives would be immeasurably poorer. Some of the best things in life are items.

Bomb
Blows up after being pushed 4 times. Leaves a crater and four crumbly blocks. Pushes blocks.

Chest
Randomly reveals a power. Stand near to open.

Crate
Burnable. Floaty. Can be climbed on from a half block. Also available in half-size.
Crates are not game cliches, they are a vital part of storing and packing other game items. Re-using them for puzzles is sensible recycling.

Fire
It Burns!!!
And it spreads, consuming all but Stone and Metal. Leaves Ash in it's wake, which stops it spreading backwards, and can set up loops.
Climb to safety if you can. Else jump in some Water quickly.

Gold
Collect all Gold and Cats to clear level.

Ice
Icy floors are slidy, unless you have Skates. Will melt into water with Heater power, as water will freeze into this with Freezer power.

IceCube
Melty. Doesn't last long when exposed to air.

Metal
Doesn't move. Even if you push it really hard. You can clone it, but can't remove it by cloning.
Also available half size.

Mine
Triggers when you approach. Kills things. Pushes blocks. Leaves holes.

Mirror
Bounces lasers. Push/Pullable. Rotatable by walking into it.

Sand
Shrinks when pushed. Can be climbed on when half-sized.

Shooter
Fires burning lasers in all four directions.
Can be walked on, built on, or pushed down holes.

Stone
Non-burny. Push/Pullable. Double-blocks split when pushed into water.
You'll be safe from animals while running on top of blocks.

Trap
Don't put your toes anywhere near this one. Worth luring Bears, Wolves and Spiders into.
Can be deactivated by standing near it and using the Defuse power, then picked up and set elsewhere.
Burns. Can be pushed down holes, or into water.

Tree
Cats hide in trees until all the aggressive wildlife has been cleared.
Don't let fire or lasers touch it until you've collected the cat from it.

Water
Wet. Non-lethal. Slows you down. Ruins Slippers or Stealth.
Cats aren't fans.
The only thing that can fill a void.
Can be reclaimed by pushing Stone blocks into it.

Void
Holey.
Shove stuff you don't want down it.