“Day of the Tentacle” is one of my favourite games of all time. I played it through as a teenager and I loved the 3 streams of play.
The basic concept is that you play as 3 friends, all separated by 100 years (Laverne in 2176, BerNARD in 1976 and Hoagie in 1776) and you have to co-operate to make sure that you can all get back to 1976 and defeat the evil Purple Tentacle (as opposed to the good natured Green Tentacle)
For example you Bernard has to retrieve a “help wanted” sign from the present, send it to Hoagie in the past so that he can get a job and deliver a battery to Laverne in the future.
It’s very complicated but wonderfully humourous. you play havoc with time (adding amendments to the US constitution so that everyone has a vacuum cleaner in the basement, just so that you’ll be able to use one in the future) and it can be a bit frustrating trying to work things out but the game is so cleverly written that it’s a joy to play.
I’ve been playing it again recently thanks to my jailbroken iPod. ScummVM is available via Cydia and it has been great playing through this and “Flight of the Amazon Queen” (now available for free!) Next up is “The Secret of Monkey Island!”