Here is the full list of all 33 Runner3 achievements.
Collect all the Narrator's Puppetshow Puppets!
Get all your friends over for some GRILLINS!
Got 'em All!
Witness something creepy.
Checkpoints? Who needs 'em!
Buy a bunch of new digs!
Get all the Gildans!
Defeat the Jungle Ruins' Boss!
Go exploring in the Retro World. Maybe you'll find a cute secret?
Buy a bunch of Accessories!
Get a Special in each Standard Level in any World!
Get a Perfect in each Standard Level in any World!
Collect all Golds and Gems and finish an Impossible Level!
Buy a bunch of Capes!
Defeat The Great Outdoors' Boss!
Head off the Beaten Path...
Invite a friend to the BBQ!
Get a Special+ and a Perfect+ in any Level!
Get a Special+!
Get a Special, a Perfect, and one Bullseye in any Level!
Make it to the end of an Impossible Level!
Bonk the Timbletot!
Defeat Machineland's Boss!
Defeat Spookyland's Bosses!
Defeat The Caves' Bosses!
Better out than in...
Defeat Foodland's Boss!
Get a Perfect+!
Get a Special!
Get a Special AND a Perfect in any one level!
Get a Perfect!
Finish all 9 Impossible Levels!
Unlock EVERYTHING!