I don’t know if it technically counts as freeware, but Space Cadet Pinball. Back on XP it was my go-to for something quick to play on the offline computer, and I just brought it with me to every new machine. Also it’s now been decompiled and will run on pretty much anything!

One of my absolute favorites is a quirky strategy game named Lord Monarch. I found it on the Nihon Falcom website way back in the mid 90s when I was first starting to use the internet: Lord Monarch

It’s super tiny in modern terms, but I remember waiting a good 20-30 minutes for it to download from a 33.6Kbps modem.

Another huge one for me was a game I actually got a full version of from a Gravis gamepad promo CD named Seek and Destroy. It’s a top down shooter where you can be either a helicopter or a tank: Seek and Destroy

The last one that comes to mind is a giant robot fighting game that also came on that same Gravis CD named One Must Fall: One Must Fall 2097

Beyond All Reason!

For the longest time I thought Minecraft was free because I only ever pirated it. Lol

PlanetSide 2 is the free-to-play I keep going back to

I always have to have Hover! on my PC. It’s hella dumb that it doesn’t just come with Windows as it did originally.

It’s been a few years, but Armagetron Advanced was the best. Felt like you were riding the lightbikes from Tron.

I’ve played Simutrans on and off ever since the mid 2010’s. I’m not any good at it, and usually play it without regard to a lot of its mechanics (especially managing finances), but I’ve spent countless of hours just connecting communities and cities with over-engineered roads, rail systems, ferries, and airplanes.

Clonk! It’s a 2D mining/strategy/base-building hybrid that was apparently more popular in Germany than other places. I actually paid to play it way back in '05, but it has since become freeware. It’s got a particle sim (similar to Noita, but not as extensive) that plays into the scenarios well.

clonk.de

Squarez Deluxe

Makes Tetris seem like a children’s toy

The Chzo Mythos games. Point and click adventure series made in AGS.

I first played 5 Days A Stranger when it was out, and it was my favourite adventure game.

Then 7 Days A Skeptic, which was basically more of the same and I thought it was very cool.

After that is Notes, which is a text parser instead of point and click. Still a lot of fun, but I always use the guide to help myself in parts.

Last one was 6 Days A Sacrifice, which I don’t remember very well, I haven’t played it as much as the other games.

Also the same guy made a game called 1213, which I loved. It played more like Flashback, cinematic platformer style.

I often revisit Soldat

I’ve been playing it off and on since maybe 2016-18 (somewhere within that range), so a pretty long time for me, but Pokemon Rejuvenation.

If you don’t mind swearing, death, and generally kinda edgy stuff, it’s a fun enough game with a lot of content. 15 out of 18 badges (one per type) are currently available, with a very long story to go with it.

Just started over on my Steam Deck, making this my umpteenth time starting over, because I felt like it and wanted to do a grass only run, similar to my fire only run. Also, unlike just about every other RPGMaker XP fangame, the devs have a Linux version available, which has an appimage instead of the .exe file to run the game and have made a bash script to update the game to replace the .exe file for that. Wine not required to play at all!

bubble tanks

Haven’t played recently, but this one came to mind’

https://en.wikipedia.org/wiki/Scorched_Earth_(video_game)

OpenTTD