Superliminal has finally come out after (apparently) 6 years of development. I've been following Pillow Castle ever since 2016 or so when I saw their demo of what would become this game.
The game is not particularly long—I beat it within two hours—but still packs quite a bit within that time. The pace is mainly dictated by your ability to solve puzzles, most of which aren't particularly tough once you grasp the basic concept.
A really strong suit of this game is the atmosphere. The art and visuals are amazing, the music is spot on, and the plot fits in perfectly. Most of this is achieved via setting constraints and then working within them, but nevertheless it turned out really well.
Even though most of the puzzles seemed quite easy after grasping the initial concept of forced perspective, some of them are quite obtuse (looking at you, Whitespace.) In general it's not puzzle-heavy like Portal, even though in places they share the same vibe.
Also unfortunately it doesn't seem that it has a lot of replay value, considering it's mostly aesthetic, but perhaps that's what games are moving towards these days.
I can't say this is a game for everyone, but if the mechanics intrigue you, or you want to experience the visuals first-hand, do check it out, especially while it's still on sale.