HyperRogue has 352 reviews. It is a rogue like that is played on a hyperbolic plane rather than a euclidian one.

If you're not familiar with hyperbolic geometry, don't be fooled by the videos. It has the illusion of looking like it is on a sphere in many of the videos. It's not! Also, you don't need to be some master of hyperbolic geometry to play. I don't really understand it but can still play the game well enough.

Essentially, imagine a hexagonal grid. Now, replace some of those hexagons with septagons (7 sided). The further away you get from a point there will be way more tiles in the hyperbolic grid than the euclidian.

The UI is pretty bad, the menus are pretty icky. Those are my only real complaints.

The game is charming. It has.a very retro feel to it. The music reminds me of something of hear from an old school point and click game or RuneScape. The graphics are minimal but charming.

The mechanics are easy enough. You get hit and you die. Most enemies die in one hit. There are no weapons or stats. It's more like chess in a way. The game will also not let you accidentally move somewhere you'd die, so, yes, very much like chess with checkmates.

Because the game is so simplistic you can get into a flow state where you quickly move and attack enemies. It's very satisfying to play.

Don't know about broad appeal, but Corn Kidz 64.

Requires a controller, looks like an N64 title, and controls like one as well. Isn't as long as some games, but it's long enough that I got hours out of it before finishing. Heard of it from someone on Lemmy a long time ago.

Has 1140 Steam reviews, so I figured it's just barely above the 1000 reviews.

Martha Is Dead is a grim psychological triller about twin sisters, set in Italy at the end of WW2. It's not about war, however. This game left me with deep emotions no other game could do. Heed the warnings given by authors, though. It may come too disturbing to some people.

Tinykin
I know you said less than 1,000 reviews but this is at 1,500 so I think it just squeaks by.

This game for lack of a better description, adorable and over too soon.

Like a mashup of pikmim, Spyro 2, and Tony Hawk Pro Skater. It's got lots of fun platforming and new puzzle mechanics in an ever adding open world that is a true joy to traverse and cute silly little side plots that make for rather grand set pieces when it all comes together. I got 100% in 12 hours but also collect-a-thons are my jam and I was plowing through the game with grin on my face for everything but the platinum time trials.

Children of a Dead Earth is a tactical space game with n-body Newtonian physics. This means that on the surface it is very similar to something like KSP, you can do things like orbit a Lagrange point. In addition, you can design all the parts of you spacecraft and weaponry down to the materials they use. If you can make a fuel tank made out of aerogel work with the laws of physics, then you can use it. For example, I made a coilgun that fires nukes which was devastating at close range but the low velocity of the nukes made them easy to dodge at long range and without any thrusters, they cannot course correct.

Taipan!

A naval trade game about 1800's China from the Apple II. You won't believe it till it happens but I'll become addicted.

Hidden and Dangerous

Only H&D2 is on steam

The original was fantastic and v2 built on that. Fantastic 3rd person WW2 tactical shooter. Haven't seen anything like it in over 20 years since.

Europa 1400: The Guild

Ignore that heretical work of The Guild 2/3 et co. Only the ORIGINAL is truly worthy.

Clanfolk, a (very alpha and also very playable) game that draws clear inspiration from Rimworld, but has a kind of tech progression that feels spiritually similar to bootstrapping a factory in Factorio, while being set in the Scottish Highlands.