These are the different achievements that can be unlocked in Silent Mobius: 7 Sins.
Chainsaw Massacre[]
Description: Kill over 100 enemies during one game with the Chainsaw weapon.
Requirements/Tips: If you try to use the slow and clumsy chainsaw against fast enemies like Hellhounds or Succubi, they will kick Sonic's tail every time. Settle for slow-moving enemies, or even better, go after Comas; they're completely stationary.
Reward:
Did You Just Punch Out Cthulhu?[]
Description: Finish off The Devourer with one punch.
Requirements/Tips: When The Devourer's nearly dead, punch him in the weak spot on his stomach and kill him. You may have to punch him more than once, but as long as he dies from one of those punches, you'll get the achievement.
Reward:
Die Another Death[]
Description: Discover every death scenario.
Requirements/Tips: Specific death scenario's happen when Sonic is killed by a certain enemy with very little health left. See here for more information.
Reward: Art Gallery #1
Endgame[]
Description: Get every ending at least once.
Requirements/Tips: See here for more info.
Reward: Rageik (male hedgehog form) skin
Find The Computer Room[]
Description: Find the only working computer in Midwich Elementary School.
Requirements/Tips:
Reward: Art Gallery #2
Fists O' Fury[]
Description: Kill over 100 enemies during one game with punching attacks.
Requirements/Tips: The weak, stationary Coma enemy will probably make up the bulk of your kills.
Reward: Metal Sonic skin
Gunslinger[]
Description: Kill over 200 enemies during one game with firearms.
Requirements/Tips:
Reward: Zonic the Zone Cop skin
Hammer Time[]
Description: Kill over 100 enemies during one game with Bludgeoning weapons.
Requirements/Tips:
Reward:
Slasher Film[]
Description: Kill over 100 enemies during one game with Cutting weapons.
Requirements/Tips:
Reward: Scourge the Hedgehog skin
Stabby McStabbity[]
Description: Kill over 100 enemies during one game with Piercing weapons.
Requirements/Tips:
Reward: Were-Sonic skin
Stamina Envy[]
Description: Find all 10 Ampoules.
Requirements/Tips:
Reward: Shadow the Hedgehog skin
Wabbit Season[]
Description: Find Robbie the Rabbit in all seven locations.
Requirements/Tips:
Reward: Art Gallery #2