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