Badger knocked yesterday's guess out of the park. It was The Dig, a classic adventure from the heyday of LucasArts point-and-click adventures (but, arguably, not one of their best).
I loved it as a kid because I remember getting it for five bucks at a market bazaar somewhere in the Inner West. Also picked up FX Fighter, which was neat, and the Mindscape-published Savage Warriors, which was truly shithouse.
Ugh. I should probably put myself through that misery again sometime, though.
Anyway! Good luck with today's game. It's a special one.