Zero Sum Game

Here is the plot of Zero Sum Game: you are an adventurer who needs to go back and undo the puzzles you've solved, decreasing your score as you do so.

This is still an unusual conceit, and even more so in 1997. However, the puzzles are fairly traditional, without particularly relying on the "undo your actions" idea: finding keys to locked doors, killing or placating enemies who block your path.

Some reviewers have criticised the game for being violent. In my opinion, this is a bit exaggerated: it's hardly the IF equivalent of American Psycho, more like a fairly gory episode of Family Guy. That said, there is indeed (non-graphic) violence against innocents on the part of the PC and others, and some (non-graphic, comedic) sexual content. What I came away with was a sense of shallowness and slapstick. I found most of the major characters funny enough, but extremely one-note. The most developed one is probably your non-speaking animal companion, which might be significant. There is a type of fantasy parody story where everyone is stupid, sociopathic and horny, and Zero Sum Game fits into that bracket.

Most of the puzzles are logical and decently clued, and some are very clever. (I particularly enjoyed how you (Spoiler - click to show)resurrect the dragon.) However, some are unintuitive. Most blatantly, at one point you need to hide in one area when an NPC comes in and drops an item: miss it and you lose the item and your chance to complete the game. There is no massively compelling reason that the player should decide to hide in this place and rifle through the NPCs belongings, and I didn't figure it out without a walkthrough.

There is some world-building, but in general, the game's world is extremely thin, throwing together a number of settings (an orphanage, a troll bridge, a castle) because they fit with the puzzles. The writing is uneven. Most of the time it feels bland, but there are also passages of slightly overwrought beauty (such as the description of the oak in the glade), and some of the jokes are very good.

A funny parody adventure for an evening or two, if you're not bothered by violent characters and immature humour, but don't expect to still be thinking about it for weeks afterwards. A game that uses the same conceit, but with (in my opinion) better writing and more inventive puzzles, is Janitor.