Here is the full list of all 34 BOMBFEST achievements worth 1,000 gamerscore. It takes around 2-3 hours to unlock all of the achievements on Xbox One.
Play a full match in Uncomfortable Mode
Unlock All Bombs and Stages
Unlock All Cosmetic Unlocks
Land in the bowl found in the Living Room
Roll two 20s in a row on the Dicey Bomb
Get a KO with a Rocket volleyed at least 2 times
Play on the secret stage
KO a player with a chain reaction involving at least 2 Potions Bombs
Catch a falling Nuke
Catch Bread and throw it back at the original thrower
Hit a single player 3 times with one Bouncy Bomb
Stick 2 Sticky Bombs to a single player
Survive when left with a single closed box in the Attic
Steal first place from the wizard during the final round.
Have a player inside each wooden house in the Garden
KO everyone with a single bomb
KO another player into the waste basket in the Study
Remove the entire tower from the Nook
Clear the stage of blocks in the Dining Room
KO 3 players with a single NON NUKE bomb
KO someone from across the stage with a thrown Ice Bomb
KO a player by pushing them into the toy car in the Toy Room
Leap across the chasm on the Deck
KO a player through one of the outside walls in the Office
Tilt the Big Duck to the side in the Bathroom
Blast a player into a Button Mine's explosion
Catch and throw away a slomo'd bomb
KO a player holding a Cotton Sword with a Cotton Sword
Fall down the drain in the Kitchen
Play a round with all bombs disabled and no timer.
KO 2 players with a single NON NUKE bomb
Get saved from an explosion by the train in the Bedroom
KO a player with a bomb they threw first
Self KO with the crown