I like how you took the ouroboros and applied it to the puzzle genre, and I also like it aesthetically.

Although I'm not a fan of the genre, I found it progressed well, even though sometimes I encountered mechanics that were explained in the next level, but I must say that the aesthetics you gave it made them quite readable.

I also tried the custom editor, and it's definitely a mechanic that will prove to be very interesting.

The modification, or bug that I encountered, not knowing if it is implemented, is that there is no continuous control over where the snake's head or body is located, making it either bodiless (like when you first place it) or headless (see screenshot), so you have to delete it and reposition it (it's not so much the effort of repositioning it that's the problem, but that I would expect it to self-adjust).

This feels smooth to play. I did have the music cut out on me periodically, unsure as to why. The audio overall was great and the sound effects felt nice for their respective actions (such as eating the black holes). I also like the little flourishes for the end of level, and how the snake keeps going behind the UI afterwards. Especially cute! As for the progression, it felt good in the first chapter of levels. It’s really easy to have them be either to easy, or jump in difficulty during the intro so I really appreciate that. Outside of the audio hiccups, my only concern would be with the undo and redo. They didn’t feel as intuitive to me, perhaps because I expect different mappings for a game than I would in a typical document or the browser. Unsure why, so that might just be a me things. UI navigation though is really nice. Although the styling feels a bit like it’s battling with the style of the game? It might be coloring or the flat colors against the starry background and texture of the snake. It also might just be my quibbling. Overall, it’s a smooth experience.

An extremely well-scoped concept executed flawlessly. The flow of the levels feels very smooth and intuitive. You did a great job introducing the mechanics gradually one at the time so that they are easy to understand. The game is a joy to play! The QoL features  are very much appreciated, especially the reset button/key combo.

The graphics and sound are good examples of being simple, but still fitting the game really well.My only suggestion is that a bit of variety with the color palette from level to level could help make your game look more appealing in screenshots to visually convey the variety your game already has in its gameplay.

This is probably the shortest review I've written and it's because I don't really have anything more constructive to say ;)

I also got the same error running on Windows 11 / Opera browser when I tried the WebGL version:

"Error
The following features required to run Godot projects on the Web are missing:
Cross Origin Isolation - Check web server configuration (send correct headers)
SharedArrayBuffer - Check web server configuration (send correct headers)"

When I tried to download the file, I got an infected malware warning!

Hey there, I'm on mac and just went to play your game in the browser on chrome.  This error came up - let me know if you need more info to trouble shoot or if you know if there's anything I can do on my end to get it to run.  

Somehow missed this game during GMTK despite searching for the couple games that went with that concept. Bit of context needed, 6 months ago I released Snakeloop (Steam|Itch), a puzzle game with the same base concept of a puzzle game based on Snake but where your goal is to eat your own tail.

I played all the way to the last level, which I failed to clear so far, and it took me a bit over 1 hour (although it’s obviously quite biased as I worked a year on a game with similar gameplay).

The game feels quite polished already, there’s quite a lot of levels already and the inclusion of a level editor is a nice thing. Now for the downsides, first is the flow of levels which feels quite weird with some of the tutorial levels being way after the first appearance of these mechanics (boxes & gates). Then the biggest issue imo is the amount of mechanics, there’s too many of them, they don’t always synergize well together and worse some are kinda incompatible with each other. Ie. there are 4 different ways you can do loops depending on the levels: loop anywhere (default one), loop on a plate tile, loop filling all the tiles and loop around galaxies. That’s too many different mechanics that can’t really go together. Imo it is best in a puzzle game to have few mechanics but have them fit tightly together and do the most with their potential, rather than having many mechanics that can be mismatched or aren’t used fully. And even with few mechanics you can end up with lots of different levels if those mechanics work well together.

Regarding bugs, I’ve had the same bug as Animamundi below with the victory animation breaking on 2 or 3 levels (don’t remember which). But a major bug was on levels with 1-way portals: Using Undo on these levels breaks all the 1-way portals with their sign all changing to the same one (and if you take any portal, they’ll all disappear).

Still, I’m quite curious to see where this project will go and will keep an eye on its development.

OK, I think I have finished the entire game... It is no way to pass through portal without ruining the path.  Should be Two Way Floor around the plate. 

Ы)

This was fun. The puzzles generally progressed well, though the portal was first used on level 9 with no instructions, followed by level 10 teaching you about them. Their use was intuitive enough, but with the instructions being on the following level, and all other mechanics being introduced with instructions, this stood out. These should probably be reversed. Levels 11 and 12 are the same level "Eat and Travel". While verifying this I noticed that the level select has the wrong names, with each being one off. Selecting level #1 loads a level with the title for #2, and so on. I've played through #16 "One Way Floor", and may play more later.

I've only taken a quick look at the level creator so far. It looks fairly intuitive, and is a nice touch. From the level editor I was able to exit back to the main screen to play the game, but I did not see an option to go from the main game back to the screen where you can select the level editor.

Definitely well done! I love unsolvable riddles! Keep it up!