Complete the game on "Hard" difficulty.
Complete the game on "Harder" difficulty.
Complete the game on "Impossible" difficulty.
Beat Volcano Research Station.
Repeat a single level 10 times.
Complete the game in 1.5 hour on at least HARD difficulty.
Complete the game in 1 hour on at least HARD difficulty.
Complete the game in 45 minutes on at least HARD difficulty.
Impale 25 enemies on hook by kicking them.
Impale 50 enemies on hook by kicking them.
Make 200 enemies die horribly by burning alive.
Maul 200 enemies to death with a sawspider.
Kill 10 enemies with a single railgun bullet.
Unlock new difficulty mode.
