The player has fully researched the Thuggish Splicer

The player has successfully invented at least one item

The player has acquired at least one weapon upgrade

The player has taken at least one Research Photo of a Splicer

The player has purchased one slot in any Plasmid or Tonic track

The player has successfully hacked a safe

The player has successfully hacked a turret

The player has successfully hacked a security bot

The player has successfully completed the Welcome To Rapture Level

Place a portal under your co-op partner while they are gesturing

Drop your co-op partner in goo while they are gesturing by removing the bridge under them

Show that pit who's boss