Here is the full list of all 15 Quantum Cortex Demo achievements.
Carry 50,000 or more credits at once.
Create a save file with your true name.
Carry 50,000 total alloy at once.
Complete the demo.
Complete the demo in under 15 minutes.
Defeat the first boss.
Defeat the second boss.
Purchase a weapon from the shop.
Have three different save slots at once.
Respawn at a checkpoint.
Complete the demo on DIFFICULT.
Buy a component from the shop.
Complete the demo on DIFFICULT without dying.
Don't tell anyone you found it.
Complete the demo without using any checkpoints.