Here is the full list of all 12 WE ARE DOOMED achievements.
Collect every Trinket in the first 10 waves
Complete Wave 30
Complete Wave 20
Zap 75 Perimeter baddies in a single Endless game
Keep a SUPERBEAM going for 10 seconds (Endless mode)
Reach Zone 6 with 80,000 points (Endless mode)
Complete Wave 10
Complete Waves 1-30
Complete Waves 1-30 with all lives intact
Zap all the baddies in Wave 9 with a SUPERBEAM
Reach Zone 10 with 450,000 points (Endless mode)
Reach Zone 8 with all lives intact (Endless mode)