Human: Fall Flat Review (soq.r)
This probably isn't the best choice for a challenging puzzle game - at least not of the brain-racking kind. In all honesty, the puzzles are as straightforward as can be. Silly physics are solely responsible for any and all challenge here because the player character quite literally plays like a clumsy sack of indeterminate substance.
To help solve the trivial puzzles, the awkward protagonist - referred to as "a human" in the game - is equipped with two individually raisable and triggerable (by mouse buttons or gamepad triggers) multi-surface-bonding hands. These can be used to operate levers to control various machinery, to place items on other items, in sockets or on switches to open doors, and next to taller objects to reach them. With a bit of know-how and coordination these hands can also be used to climb walls to skip sections of levels and to complete certain challenges for achievements in hard-to-reach places.
Frankly, the game can frustrate to the point of feeling outright tiresome. Movement speed is not the fastest. The "human" does not get to build anything more complex beyond inserting one or two missing bits in a mechanism. Picking up smaller objects requires a degree of precision - the hand might miss it and get stuck to the floor instead. Grabbing some adjacent surfaces when climbing is occasionally a bit unreliable. The game may feel very lonely in single player mode because there are no characters to interact with and no story to tie the abstract levels together. The musical score and the background sounds are sparse.
That said, if the mechanical peculiarities, general simplicity, and audio-visual minimalism are not too off-putting, then perhaps there is a calming, introspective experience to be found here. Losing is impossible - there are no enemies to fight, and the player character, along with all objects necessary for the completion of a level, will respawn should they ever find themselves out of bounds. Because of overbearing loneliness the rare bursts of uplifting music triggered by making progress become all the more pleasant and inspiring.
There are quite a few little challenges to perform in every level for achievements. These challenges are not too difficult but can still be enjoyable, although a few of them have ambiguous descriptions, are finicky, unintuitive, and sometimes even buggy with regard to how their respective achievements get awarded. Despite this, at the end of the day they all worked, and every single one of them is possible in single player mode - even those which require going into the two festive multiplayer lobby levels. Multiple extra levels, each governed by a theme, with their own achievements have been added since release. Unfortunately, the game features checkpoint saves only, and levels don't tend to loop back conveniently, so some achievements might necessitate starting the level again if anything is missed along the way because sometimes going back after a checkpoint is either impossible or would be too inefficient.