Full list of all 57 Riverbond achievements worth 1,100 gamerscore. It takes around 4-5 hours to unlock all of the achievements in the base game on Xbox One.
The base game contains 52 achievements worth 1,000 Gamerscore, and there is 1 DLC pack containing 5 achievements worth 100 Gamerscore.
Speak with with Mr. Oopay
Destroy The Knight
Defeat All Bosses
Speak with Eldra Highest of High
Speak with Eldra Rex
Collect 35 Stars
Speak with Eldra the Spirit
Begin the eighth adventure
Waste Koke the Crab
Speak with Sunlight-Rising-Boldly
Collect 25 Stars
Speak with Spirit-Running-Softly
Begin the seventh adventure
Exterminate Column XVII
Find the secret room in the museum
Speak with Hamdalf
Begin the sixth adventure
Defeat Puffy the Lurker
Speak with Hamdini
Find the secret cave in the desert
Speak with Ham Solo
Unlock 35 Skins
Defeat 20 enemies with any Slap Weapon
Collect 15 Stars
Begin the fifth adventure
Shatter Romeo Ur-Ribitt
Find the secret storage area in the swamp
Speak with BOMB GIRL in the Swamp
Begin the third adventure
Wipe Out Rabbitus Maximus
Speak with Larry the Lost
Defeat 20 enemies with any Club
Unlock 25 Skins
Speak with Peaceful Pig
Begin the second adventure
Complete the tutorial
Unlock 15 Skins
Wreck Captain Barbacus
Defeat 20 enemies with any Dual Weapon
Speak with Big Bob
Find the secret beach
Defeat 20 enemies with any Spear
Speak with Waterkeeper Wyn
Collect 5 Stars
Begin the first adventure
Slay Pumpiron Pengo
Unlock 5 Skins
Defeat 20 enemies with any Gun
Speak with Fur
Speak with Hoota tha Skoota
Defeat 20 enemies with any Sword
Begin the fourth adventure
Speak with Brother Honey
Die by Traps 20 Times
Defeat Great Cartos
Kill 80 Slimes
Begin the Ninth Adventure