Mushroom Cats has a total of 24 Steam achievements, none of which are missable. All achievements can be earned in a single playthrough taking around 5 minutes to complete.

The game is entirely controlled with a mouse, you move around the play area by moving the cursor to the edges of the screen (up, down, left and right). Hats are collected and placed simply using the left mouse button.

Note that at the time of writing, Steam is still "learning about this game" so achievements will not yet count towards profile totals, I'm somewhat unsure of the "learning" process, but given the positive reviews, it should only be a matter of time until they count towards profile totals.

22 of the 24 achievements for Mushroom Cats are earned by locating red and white Christmas hats and placing one upon the head of each of the 22 cats in the game. A hat is collected by moving the mouse cursor over the hat and picked up by pressing the left mouse button.

A hat is then placed upon the head of a cat by clicking with the left mouse button on the cat, when you have a hat in your inventory. The number of hats in your inventory is shown in the bottom left of the screen.

The "Winter!" achievement pops when you have unlocked all 22 of the "Hat on!" achievements.

For the "Happy Sun!" achievement, move the mouse cursor over the spinning sun in the top left of the play area and repeatedly tap the left mouse button to speed the spinning sun up until the achievement pops.

Video contains...
@ 0:06 = Cat #1
@ 0:14 = Happy Sun! achievement.
@ 0:20 = Cat #2
@ 0:37 = Cat #3
@ 0:39 = Cat #4
@ 0:42 = Cat #5
@ 0:47 = Cat #6
@ 0:48 = Cat #8
@ 0:53 = Cat #10
@ 0:56 = Cat #11
@ 0:58 = Cat #9
@ 1:02 = Cat #13
@ 1:05 = Cat #12
@ 1:08 = Cat #14
@ 1:10 = Cat #15
@ 1:15 = Cat #16
@ 1:15 = Cat #17
@ 1:17 = Cat #18
@ 1:22 = Cat #20
@ 1:25 = Cat #21
@ 2:29 = Cat #7
@ 3:19 = Cat #22
@ 3:24 = Winter! achievement pops.

I hope you found this guide of help, all comments, suggestions and criticism (constructive) is gratefully received.

An A to Z list of my Steam achievement guides and walkthroughs can be found @
https://cs2bus.com/sharedfiles/filedetails/?id=1502405720
If you would like to get a notification in your activity feed when I post a new guide, just click the "follow anrkyuk" button on my profile guide list...
https://cs2bus.com/id/anrkyuk/myworkshopfiles/?section=guides