Oasis - A great ministrategy game that I think is impossible to get now, unfortunately. It’s Minesweeper meets Civilization. Seriously.
Knytt Stories - A free platformer by an indie dev named Nifflas. There is a level editor that lets you make your own games with it and once upon a time there was a small but vibrant community making some pretty good custom stories.
Alien Legacy - A space strategy/narrative game by Joe Ybarra, who was the producer for the Starflight games. It feels a bit like Star Control, but it takes place in a single solar system. You explore, collect resources, build colonies, and pursue a fixed story that develops as you spread yourself to the various planets. Very playable these days, though it would require some patience. Unfortunately, I think it can only be acquired from abandonware sites right now.
A Mind Forever Voyaging - This is an Infocom text adventure. It’s different from all the others in that it’s not really about puzzle solving. You are an AI that lives inside a simulated world. Researchers are using that simulation to test the effects of some new conservative policy proposals. You basically have to go around this simulated city and record yourself completing a checklist of typical activities, then you jump ahead some number of years in the simulation and do it again, seeing how things change.
Super Crate Box - The first game by indie darlings Vlambeer (Ridiculous Fishing, Nuclear Throne). It’s an endless shooter-platformer where random weapons drop to you and harder and harder monsters come after you. It’s free and worth checking out.
Project: Space Station - A very early Apple II and DOS game from the 80s. We’re tlaking CGA graphics! I believe it was made by Larry Holland, who went on to make X-Wing and TIE Fighter for Lucasarts! It’s a strategy game of running a space station–flying shuttle flights with modules, crew, and supplies; launching satellites for cash; and running research projects. It’s not easy to look at anymore, and there are some clunky design elements, but I still enjoy playing it. Someone needs to remake this game.
Mission Critical - An adventure game by Legend Entertainment. Imagine System Shock with the monsters removed, as a point-and-click game. You’re the only person on a damaged ship and you have to figure out how to survive and complete the ship’s mission. There’s a little spaceship strategy game built in, too. Very good, and available on GOG!
Gold of the Americas - An older light strategy game for DOS, just predating Civilization, I believe. It’s European powers being all imperial and settling the new world.
NightSky - Another game by Nifflas, who made Knytt Stories. It’s got the silhouette look of Limbo, but is much more chill. You’re just a big marble making your way from left to right. The kinds of puzzles and gizmos that the designer came up with to challenge a rolly marble are pretty impressive! It’s on Steam.
Suspended - Another Infocom game. Maybe my favorite, but really hard. It’s also not typical text adventure puzzle-solving. In the future, the world is run by automated systems that make life hassle-free. This society puts one human being in suspended animation every hundred years or something, to be woken up if anything ever goes wrong with the systems. But that wouldn’t happen! Except it happens, and you have to fix all these malfunctioning systems by inhabiting five robots that all have different capabilities and ways of sensing the environment.
Candy Box - One of the first idle games, but also (unlike nearly all its descendants) a game full of surprises that just gets bigger and bigger as you go. Definitely worth taking a peek at, since it’s free in your browser. (The link is Candy Box 2. I don’t know if 1 is still available.)
The Dark Eye - Not to be confused with some recent RPGs (I think), this is an adventure game from the post-Myst CD-ROM days based on Edgar Allen Poe stories. It’s not really a great game, honestly, in that way that a lot of CD-ROM games were sub-par experiences. But it’s got an amazing art style, using these sculpted puppet-like characters to tell its stories. And a few of the stories really made an impression on me. If you happen to know who cult author William S. Burroughs is, you should check out his dramatic reading of Masque of the Red Death from the game.
The Oil Blue - The guy who made this went on to make Cook Serve Delicious, and it shows. It’s a time management game where you are collecting oil by using a few different oil-drilling machines. You have to jump between them to keep them running properly and to extract oil efficiently. It quickly gets hectic. Cook Serve Delicious is probably a better version of this game, frankly. It’s on Steam.
Vessel - A great PC/Console platformer centered around fluid motion simulation. You are a dude with a liquid-sucking vacuum thing on his back. You use it to solve puzzles by moving fluids around, including living slime stuff. It’s super clever and very well made. Great soundtrack too, if I recall.