While Day of the Tentacle is more famous than its
predecessor, especially to the late-comers of the
adventure game frenzy of the late 80's/early 90's, it is not nearly as
massive in scope or as
brilliantly designed as the game that came before it -
Maniac Mansion.
Day of the Tentacle took the premise of a mildly scary, dark-humored adventure game, and turned it family friendly. Nothing wrong with that, I guess. It makes for a more 'pleasant' gaming experience - although it seems to negate all the horribles that were going on in the last game.
The thing that was a genuine disappointment to most Maniac Mansion fans was that Day of the Tentacle had a very rigid design structure. While a lot of the puzzles could be solved out of order, there was only one solution to them, and only one ending that could come out of it. Whereas Maniac Mansion had a gazillion different solutions (you could choose to play eight different characters, and - legendarily - you could beat the game with any combination), and a hitherto un-counted number of different endings.
But in what is, in my opinion, a brilliant strategy move, Day of the Tentacle included Maniac Mansion as a game-within-a-game. Go to Weird Ed Edison's room and use his computer. WHAM. And they even removed the copy protection.
Shh, people - don't let everyone know that you can rename the .DAT-file in the MM-directory on the CD to .EXE, and use the game without booting DOTT first! *looks around nervously and hides*