Here is the full list of all 21 Tachyon Project achievements.
Kill 50 enemies in less than 1 second
Finish a wave with less than 1 second left
Finish the tenth level
Leave a Decoy and a Turret right after
Finish the ninth level
Spend a total of 10 minutes hidden
Finish the eighth level
Finish the fourth level
Finish the fifth level
Finish the sixth level
Finish the seventh level
Destroy 2500 enemies
Destroy 10000 enemies
Destroy 100 bulls
Destroy 100 Shield Bearers
Spend 15 seconds hidden in one go
Finish the first level
Finish the second level
Finish the third level
Destroy 500 enemies
Destroy 10 enemies with a single explosion