I can think of two magnificent games: "Ib" and "Pony Island".

Simply new-to-me:

I'm currently playing Hands of Necromancy and Voodoo Vince Remastered, which I hardly knew anything about before buying. They may not be outstanding games but I was positively surprised by how much I enjoy them.

Hands of Necromancy is a commercial GZDoom mod in the vein of Hedon (which I like very much as well), meaning it also has a fantasy theme and magic-based weaponry plus rather large levels to explore and backtrack in. The latter may not be to everyone's liking, but it suits me very well, as I'm rather the "check every nook and cranny" type and less so all about running and gunning only. A special feature it has are spells that can you turn into other creatures stronger or smaller than the default wizard character, thereby opening up new paths (and adding a little Metroidvania-lite note to it). The transformations also come with their own special attacks. So far, there were only three minor things I did not like about it: 1) The singular voiced line your character says at the very beginning, which is bad enough to ruin immersion for a short moment, but thankfully quickly forgotten again, 2) Those 2.5D melee enemies like gargoyles and piranhas which can make you feel like you're fighting papercut opponents randomly giving you paper cuts, heh. 3) It actually has a Necromancy spell allowing you to raise defeated enemies, but their AI and pathfinding is terrible, so it's not all that useful. Otherwise, very fun game to me.

Voodoo Vince was originally an Xbox exclusive, it seems, and came out in 2003, which means it actually predates Psychonauts, even though at first sight it may look like it's trying to mimick it a bit in style and gameplay. It's nowhere near as funny and complex as Psychonauts, of course, but it does have a couple of original ideas, neat settings and opponents, plus nice music and funny sound effects. It also controls a bit similar. So far it was extremely easy in terms of fighting enemies, like no challenge at all, but I was pleasantly surprised by how enjoyable I found it to jump around and explore the levels, and there was quite a bit of variety already, including adventure game style puzzle solving.

Dex is one. If you like cyberpunk fiction, if you like Metroidvania games or if you like RPGs, it's worth checking out. If you like all of those, it's doubly worth checking out. It's not perfect (its hacking minigame is trash) and it's relatively short, but it's still such a fun, digestible game. I actually recommend checking out the demo first, as the demo was so good that it made me want to buy the main game. For example, just as a thanks for checking out the demo, you can get some free goodies (some of which aren't included in the game's purchase) and I really love how the trailer at the end was woven into the narrative, rather than feeling like a "buy now to get all this!" sort of thing as it is in most demos.

These words of yours immediately made me think of at least three games. They're all Japanese (surprise surprise) and probably you know at least one of them already, however they are:

- I'm Sorry (arcade)
- Takeshi no Chōsenjō (NES)
- Seaman (Dreamcast)

I recall a couple other Japanese games involving naked bodybuilders, but thankfully I can't rememebr their names.

PS
There are the well-known Frankie Goes To Hollywood and Weird Dreams for home computers as well.

itch.io is a huge rabbit hole of weird and strange games. You can start with games that are specifically tagged weird:

https://itch.io/games/tag-weird

Probably old news to many, but not to me...

The other day I was looking at a site akin to "50 games like _______" and was struck by the amazing art direction on...

... the ISHAR by Silmarils

I came back to GOG and found the ISHAR series (https://www.gog.com/en/game/ishar_compilation).

Wondering what Silmarils did next, I rooted around and found...

... an early 3D hack-n-slash RPG that looks like a dash of RUNE and SEVERANCE BLADE OF DARKNESS...

... ASGHAN THE DRAGONSLAYER

Sadly, the game seems currently lost to the abandonware bin. Silmarils really had some style!

gameplay: https://www.youtube.com/watch?v=6_f9xz69nTc

wishlist: https://www.gog.com/wishlist/games/asghan_the_dragonslayer

I wonder how many people overlook the absolute blast that "Guns Gore and Cannoli" is.

Or underestimate how enjoyable and charming and fun "Puzzle Agent" turns out to be.

Or haven't ever tried the "Cube Escape / Rusty Lake" games. Or even any "Creeper World".

Super Daryl Deluxe it's a very weird but wonderful game

Core Design is mostly known for the classic Tomb Raider series, but developed many other games such as Herdy Gerdy, for the PS2 console. It was a rather cute game that revolved around shepherding creatures to a desired location. It looks like a platformer at first glance, but it's mostly a puzzle game, the challenge comes from figuring out what is the safest/efficient way to herd creatures; the way they interact with their environment and each other can help or hinder the player. To be truthful, I eventually quit the game because I was unable to beat a timed challenge that was mandatory to progress further, but was interesting experience while it lasted.

The games that come to mind are Downwell and Townscaper.

Downwell, as the name implies, follows your character jumping down a well with their trusty boots that can fire lasers. It's a fun game, and I don't think there are other games like it at the moment. As for underrated, I'm not sure, since I have a feeling that people might have at least heard about the game somewhere before despite never actually seeing the game itself.

Townscaper is basically just a simple relaxing building game where you get to construct your buildings on the vast ocean. That said, you don't get to choose the tiny details that the buildings might have after they have been erected (such as where will the windows be, the doors, etc.). But there are tips and tricks that can help you minimize that randomness, by getting the placement of the buildings in a certain manner. My only gripe with the game is the lack of people. Meaning, you'll only be seeing an empty world devoid of any humans, just birds (Yep, birds are the only living things in the game).

Oh and one more, Pathologic. The game's not underrated I'm sure, but the whole setting in which the game takes place is just too eerie to not be included into the list.

Worth noting that the second game was apparently designed by a man who hates videogames, and was therefore designed, on purpose, to not be fun.

(Still probably more entertaining than, say, Desert Bus, which is another famous example of a game designed, on purpose, to be boring.)

Also of note:
* Downwell is rather short, which is perfect for a game with roguelike mechanics (including permadeath); a death, even late in the game, won't cost much time.
* Downwell is also priced according to its length; it's only about $3.

Other games that come to mind:
* Super Hexagon: Another short $3 game; I believe this game basically has you dodge things on a hexagon. It's apparently quite difficult. (I've seen the game in action, but haven't played it myself.)
* VVVVVV: A 2D precision platformer where you can't jump. Instead, you flip; by pressing a button while on solid ground, you can flip yourself and start falling upward. Once you're on the ceiling, you can flip again if you need to go back to the floor. This is the game's core mechanic, and you actually can't pass through the second room without doing so.

I don't know if you know about this one, but there's also another unique game that I found called Super Puzzle Platformer Deluxe here on GOG, and I think it's a combination of tetris and platformer. Never played it myself, but it definitely looks fun for its price.

After a lot of recent hype, I just started playing Vampire Survivors and I am instantly hooked on it.