Here is the full list of all 35 Time Rifters achievements.
Destroy 50,000 enemies with the Plasma Beam
Get 100% on Episode 2
Record a Let's Replay on any Episode
Destroy 5,000 enemies with the Particle Ball
Destroy 5,000 enemies with the Flak Cannon
Destroy 5,000 enemies with the Scatter Pistol
Destroy 5,000 enemies with rockets
Create & Upload a Custom Arena
Create & Upload a Challenge Room
Destroy 5,000 enemies with the Spread Rifle
Unlocked Experiment mode for Episode 3
Destroy 500 enemies with the Spread Rifle
Escape every arena in Episode 2
Escape every arena in Episode 3
Escape every arena in Episode 1
Complete a Let's Replay on any Episode
Play a Custom Arena
Complete 1 Daily Challenge
Destroy 500 enemies with rockets
Unlocked Experiment mode for Episode 2
Destroy 5,000 enemies with the Plasma Beam
Destroy 500 enemies with the Particle Ball
Get 100% on Episode 1
Unlocked Experiment mode for Episode 1
Destroy 500 enemies with the Flak Cannon
Destroy 500 enemies with the Plasma Beam
Destroy 500 enemies with the Scatter Pistol
Get 100% on Episode 3
Destroy 50,000 enemies with rockets
Destroy 50,000 enemies with the Particle Ball
Destroy 50,000 enemies with the Flak Cannon
Destroy 50,00 enemies with the Spread Rifle
Destroy 50,000 enemies with the Scatter Pistol
Complete 10 Daily Challenges
Complete 50 Daily Challenges