For once, a classic runs better on the Mac.
Gameplay:
Point and click. My only gripe would be that clicking the actions first can get tedious and walking takes a bit too long.
Graphics:
You've got to remember, this game is old. And back then, these were the best you get. Even today they are perfectly recognisable.
Sound:
Good, but some of the voices *cough*Laverne*cough* sound completely uninspired. Still, state of the art for the time.
Value:
You'll have a blast the first playthrough, but there isn't much to come back to after.
Overall, for a few bucks, Maniac Mansion is well worth it. But take note, for it only runs on older Macs.