Here is the full list of all 51 Unit 4 achievements.
The base game contains 44 achievements, and there is 1 DLC pack containing 7 achievements.
Clash of Agents: Complete a game of Bouncing Madness
Clash of Agents: Collect 80 coins during Bouncing Madness
Clash of Agents: Complete a game of The Great Climb
Clash of Agents: Reach 8.0 meters in The Great Climb
Clash of Agents: Complete a game of Space Brawl
Clash of Agents: Defeat 40 enemies in Space Brawl
Clash of Agents: Complete each competitive minigame