Bouncy Bombs - turns all blocks affected into trampolines.
Goo Bombs - dyes all blocks a certain color.
Elevator Blocks - pushes anyone near them in a certain direction.
Tool AOE - replaces level 5 aoe boon with a three by three pattern forming a tunnel.
Light Blocks - invisible block that adds ambient light.
Snowball and goo, goo ball! Throw at a player or creature to turn them that colour for a couple minutes.
Decreased gravity (DG) and increased gravity (IG) boon for bombs and maybe slingbows.
You hit with DG a mob and it starts floating then you hit with IG and it gets pulled to the ground taking fall damage
sorry all my sugestion are super crazy fun and serious
New type of slingbow that can hurt players holding the same type of bow.
An exo planet with rock and ground at elevation 255 to 100. And hollow from mantel to elevation 100
Saddles for cuttletrunks
Any block that could add player buff. Ex: road blocks that add run speed. Fortress block that adds damage. Obstacle block that adds jump height.
Oh lol that would make even more stupid when I hit other citizens thinking they are Cuttles
Landing blocks that slow your fall down to normal walking speed before you hit them. I want to make drop downs without adding liquids or slides at the end.
So players that want to PvP can do so anytime, anywhere. Cool idea. A lot of ppl would probably love it lol. I am zero interested in PvP in this game, but if I can’t be effected by it in any way, I think it could be fun for those that do want it. 
Donkeys.
.
Bareback T6 Moose riding races!
Toilet seat on which you can rest while AFK 
Fake lava blocks on which you can walk, and can be seamlessly mixed with real lava blocks.
Warp bombs, can throw them out and temporarily opens a warp that puts you through to a random different part of that planet.
Heavily decrease impact damage.
hahahaha… hah…
Semi-serious-not-so-serious:
I really REALLY want Bouncy Feet quirk to negate all fall damage. I would go exploring just to go bouncing down mountains… Tribes-ski style =D. would be so fun to play with!
Also, Underwater Breathing. somehow. potion… boon… skill… whatevs. Theres a whole world underwater in some of these planets, no one ever sees. this mechanic would change the game son!
chisel bomb - smoothens blocky terrain
Fireworks!!! You setup the pyrotechnics display and every day it repeats the show complete with Fantasy in the Sky music from the Disney fireworks!! 
Wait…actually THAT would be pretty darn cool!!! Lets do that!!!
Flying mounts
Personal shields
Dungeons #hytale
Spaceships and space battles #starbound
creatures specific to one planet
Protectors “that come in many forms”
Titans
Oort Temples
At first I was gonna say “but that’s a serious suggestion”
But maybe not haha
one uber donkey is enough i think