Here is the full list of all 46 Runbow achievements worth 1,000 gamerscore. It takes around 10-12 hours to unlock all of the achievements on Xbox One.
Get the Mimicry power-up 10 times
Do 20 taunts in one game and win
Be stunned when you get the trophy
Win a tie-breaker
Get hit by lighting 10 times
Taunt 20 times
Set the fun type to Kawaii
Set the fun type to Maximum
Get the Swapper power-up 10 times
Land 5 super punches
Play King Of The Hill
Play Arena
Land 20 hits in one game and win
Beat 100 enemies
Do 10 Butt Pounds
Fall to your death 20 times
Beat 10 Adventures with a friend
Land one of each attack
Break 30 breakable blocks
Play a Run game
Spend more than 3 minutes in the air
Beat Satura in Forgotten Forest
Beat all of Forgotten Forest
3 medal all of Forgotten Forest
Beat Satura in Lost Luau
Beat all of Lost Luau
3 medal all of Lost Luau
Beat Satura in Break-Out
Beat all of Break-Out
3 medal all of Break-Out
Beat Satura in Monster Manor
Beat all of Monster Manor
3 medal all of Monster Manor
Beat all levels in Adventure mode
3 medal all levels in Adventure mode
Beat Adventure mode and defeat Satura
Unlock all Gallery content
Unlock every guest character
Beat the Bowhemoth
Beat the Bowhemoth in 60 deaths or 60 min
Beat the Bowhemoth in 10 deaths or 20 min
Get 3 medals in 10 Adventure levels
Get 3 medals in 15 Adventure levels
Play a level in each Adventure map
Get killed by a laser
Play a Lot