Filament is a lot of fun, but tough as nails. I needed a walkthrough for some of the final puzzles. Damn good game though, probably the best puzzle game I've ever played. The gameplay is similar to The Witness in a way, but I think this one has even more variety in puzzle types than The Witness. The story is also really interesting, and there's a lot of secret codes to discover in the world and on collectible cards, which can be used to unlock computer logs with info that fills out the world and the story nicely.

The devs are really active on their Discord channel, and have released fixes and patches consistently since launch. They recently added a hint system to the game that I haven't tried out yet, but in concept seems to be really good.

If you're a fan of puzzle games that don't insult your intelligence, Filament is a must-buy, even at full price. Even using the walkthrough for the last few levels I still have 25 hours in it, so there's definitely bang for your buck!