Maniac Mansion was one of my favorite adventure games growing up. I found out that if I fill up the pool while someone was still in it, the character would die with a little gravestone outside the house. Are there any other ways to kill your characters in this game?
Here there be spoilers.
This list is abbreviated from ManiacMansionFan:
- If your copy has copy protection, enter the wrong code on the security door. (Once the alarm starts, if you don't get the right one very quickly, ka-BOOM!)
- Turn off the power in the basement. Once again, a few minutes later, and ka-BOOM!
- Drain the swimming pool with the water valve. Once again, a few minutes later, and ka-BOOM! (Are we sensing a pattern yet?)
- If you have Bernard, and the steel security door is in place (whether or not your copy is copy-protected), have Bernard read the instructions for the door. He'll try to crack it, and ... Oh, OK, you get the point.
- Get into the secret lab and wait for Dr. Fred to activate the self-destruct mechanism.
- Enter the Meteor's room without a radiation suit and let the radiation wave hit you.
- Blow up Ed's hamster in the microwave. Pick up the hamster guts and give them back to Ed. He will not be happy, and that kid will be dead.
- Copy the tentacle mating calls record on the cassette tape and play it for the green tentacle.
- Tape Syd or Razor playing the piano, send it to Mark Eteer, and then show the record contract to the green tentacle.
- With Wendy, get a publishing contract for the meteor, and show that contract to the green tentacle.
- You already listed this in the question, but for completeness, drain the pool, have a kid climb in it, then refill the pool while the kid is still there. Buh-bye.
- Fill the glass jar with radioactive water from the pool. Heat it in the microwave. Open the microwave. Enjoy your last few moments with the fumes.
(I should note that many of these can also be avoided once you've triggered them, by undoing the action -- turning the power back on, refilling the pool, etc. -- before the time limit is up.)