Easter Eggs in JAPNCA (spoilers)

[Blackdrazon]

Is it possible to get all three keys in the first half (read: currently released) version of JAPNCA?  I only found it thanks to a walkthrough (darn that laundry chute!  I just couldn't find it!) but now I'm just too curious to let it go!  I keep trying to interact with other Adventure Game references (such as the Tentacle bush) but no luck yet, maybe I'm just not trying hard enough.

If anyone knows anything, I'd be very grateful!  Thanks!