Catoscope

Two cats sit side by side. The left one is correct.
The one on the right is not. His head is swollen. His ears went somewhere and did not come back. He swears his paws were longer this morning, and he has been stretched along a line nobody remembers drawing. The file simply calls him the specimen, and now he is your problem.

You fix him with glass.
Under the panels lies a tray of lenses — magnify, shrink, widen, flatten, swirl, bulge, pinch, shear, ripple, and a void that quietly cancels whatever it covers. You pick one up and lay it on the cat. Slide it. Grow it. Turn it. The cat bends under it, live, as you move your hand. Somewhere in that small space is the exact spot where the swelling meets its opposite and simply stops existing, and when you find it the two cats snap into agreement and the level is over. You will know before the game tells you.
Nothing here can be failed. The clock in the corner counts up, but it is not counting down to anything, and nobody is going to take the cat away from you. Your stars come from moves, not minutes: solve him in par and you get all three, take longer and you still get the cat. The only thing this game ever asks is that you look at him long enough to see what happened.
FIFTY CATS, IN FIVE CABINETS
The first cabinet teaches you to look. The second starts tilting things, and suddenly a lens has to be turned as well as placed. The third cabinet betrays you: one day you open a level and the wrong cat is the one on the left. Nothing is broken on your side at all. Your job is no longer to fix him — it is to reproduce, faithfully, whatever was done to the other one. "We stopped keeping the original," says the note. "This is the original now."
By the fourth cabinet there is more glass on the board than cat. By the fifth you are handed the void, and the void looks back.

Twenty breeds pass through on the way — tabby, ragdoll, chonk, sphynx, and one the file only calls "eldritch". Every one of them leaves whole.
Every level says what it wants of you in one plain line under the panels, and no level withholds anything to seem clever. When a mechanic is new, the game explains it once, in the words of whatever you are actually holding — controller, mouse or thumb.
THE WHOLE CABINET
When you have seen all fifty, you can run them. Fifty cats back to back and a clock that finally means something. Every cat is timed as its own split, so you will find out exactly which one keeps costing you the run, and finished runs go into the records table to be beaten later — probably by you.
BEND YOUR OWN CATS, AND HAND THEM TO STRANGERS
The level editor is the other half of this game, and it does not talk down to you.
There are no sliders and no vocabulary to learn. You drop a ring onto a cat and bend him with it: drag the middle to move it, grab the rim to make it bigger, roll the wheel to bend harder. The cat deforms while you do it, so you are never editing numbers — you are pushing on a cat. From every ring a wire runs down to a slot in the tray, showing the exact lens the player will be handed to undo what you just did. One lamp tells you whether a human being can actually solve this. One number, Room To Miss, tells you how much they are allowed to be wrong. Easy, Normal, Tricky. Name it. Done.
Then send it out.

Publish a single cat or a whole pack of them straight to the Steam Workshop, and anyone who owns the game can subscribe and play what you made. Their levels arrive the same way: one click, and someone else's bent cats are sitting in your cabinet next to ours. Nothing is second-class about them — a level built by a player on their sofa runs the same twelve lenses, the same solver and the same three stars as the fifty we made ourselves.
So fifty is only the number we shipped. The cabinet keeps filling up.
MADE TO BE PLAYED COMFORTABLY
Mouse, keyboard and controller work on every screen, editor included. If dragging is awkward, place a lens with a click instead. Text comes in large and largest, with high contrast and reduced motion for anyone who needs them, and stick speed you can set yourself. The music changes as you go deeper. Two hundred cat facts arrive whether or not you asked for any.
Fifty cats of ours, and as many more as the Workshop can stand. A hundred and fifty stars, three per cat if you solve him clean. Five achievements, one of them hidden. And at the end, a sentence that has been waiting for you the whole time: thank you for looking inside.