These are my initial thoughts:
Lime Ergot and CC’s Road to Stardom are both short, well-written games with some neat features. Lime Ergot is super influential (in that quite a few games are based on it, many of which themselves were successful, and it’s been mentioned in dozens of threads on this forum), but was written really fast and is sparse. CC’s Road to Stardom is less known, but it has great pixel art and polish.
Nightfall and Perdition’s Flames is a matchup between two masters of TADS: Mike Roberts and Eric Eve. Perdition’s Flames is so old it predates Inform (or is close to the release of Inform), which for the games that show up on this forum that aren’t commercial, that’s pretty old. It’s fun and funny, but firmly in that time period. Nightfall is also firmly in its time period, a polished game that came out around the time of Lost Pig and Violet, with tons of custom responses, smooth synonyms and command recognition, and character-driven story (in this case, a character who isn’t there).
A Change in the Weather vs Dark Room is a real toss-up, but I see it being pretty one-sided (I just don’t know which side yet). A Change in the Weather the hardest IFComp winner, and to me represents one of the biggest influences that led to story-focused (and eventually puzzle-light) gameplay. A Dark Room, though, is a brilliant and innovative clicker-type game that is really fun. This really is apples to oranges, so I think it will come down to whether this audience is more of an apple-audience or an orange-audience.
Over Here! and Lost Labyrinth are both nostalgic old-school games, but in very different ways. Over Here! is a text-light pixel art-heavy Adventuron game packed with dense puzzles in a very symmetric grid of rooms with minimal story. Lost Labyrinth is a sprawling and, well, Labrynthine game that does have a lot of puzzles but is more story-focused and has a more linear playstyle (only when compared to Over Here!).
Taco Fiction is Ryan Veeder’s breakout hit and has a ton of the things that people love about his work, like fun text effects, dynamic characters, side material that is highly implemented despite not mattering for the ‘speedrun’ path, and funny, unexpected game moments. Eidolon is a haunting game that stirs up childhood fears and has great atmosphere. It’s Twine, and long. I’m holding off on voting here until I replay these games.
Inevitable is a game by Kathleen Fischer, who, to me, is the best ‘lesser-known’ author. She has 3-4 great games, nice puzzles, cool atmosphere, but never won a big award and isn’t discussed much now. This game is her best puzzler, and is in the genre of ‘explore alien ruins and experience memories’. Word of the Day, on the other hand, is a sci fi murder mystery game set on a spaceship where someone has sabotaged everything. Both have a lot of great worldbuilding.
The Edifice is an early IFComp winner where you ascend different tiers of a monolith (which I’ve been told is not inspired by 2001) to experience different parts of the evolution of humankind, and is most famous for a language puzzle. This is in stark contrast to Pogoman GO!, which is highly technology-focused and features both a parody pokemon minigame (which takes up a huge amount of code) and a villainous Elon Musk. I’m going to replay here, too, before voting.
The Mystery of Winchester High is a Garry Francis highschool investigation game that, if I remember, has some puzzles that use the same objects in multiple ways and has some good polish and investigation. Sand-dancer is Aaron Reed’s tutorial programming game from his book, and includes a lot of compelling characters and vivid cutscenes.
A lot of tough decisions here, and some votes I’ve already cast I’ve thought of switching. Should be fun!