An exercise in 'how well do you know your IF parser?' I've compiled a list of actions with unique responses in the spoiler space; it's probably incomplete, but is longer than the Club Floyd list and includes some amusingly silly responses. A few typos, but it's fast and fun.
(There is no apparent reference to Suzanne Vega's 'Small Blue Thing', which I will admit was my go-to visualisation for the Blue Thing - the THMBGs song being slightly vague as to description.)
(Spoiler - click to show)
About
I
N
E
S
W
NE
SE
Up
Sing
Dance
Stop
Cry
Fight me
Remember
Forget
Sleep
Wake up
X ideas
X blue thing
xyzzy
Wait
Pray
Curse
Smell
Listen
Think
X me
X doorway
X road
X stairs
Take stairs
Take doorway
Laugh
Hit stairs
Hit doorway
Hint
Urinate
Eat door
Credits
Recommended for: when you're in a methodical mood.