Luster

This game was one of the last place entries in IFComp the year it came out. It's a traditional treasure romp where you gather 4 gems and then put them in a museum.

It's buggy quite a bit; examining a sign can switch the room you're in, there's no way to get a "You've won" message, and some items have names like pedestal3.

Someone went through several years later and decompiled the game and wrote a walkthrough and made a map. The map and walkthrough are fascinating, and provide an interesting insight into game design.

Recommended (with its walkthrough) for those who are interested in writing games.