Hi there!

There are a list of improvements and additions at the bottom of the game page, but I can go into some more detail.

While the core gameplay of knocking things onto the floor remains the same, the progression systems were completely redesigned. In the original game, all levels were procedurally generated, there was a lot of randomness with how you experienced new content, and it didn't track much of your progress. In Remeowstered, there's a new Goals mode with persistent levels where you complete various tasks to unlock new levels (in addition to a Procedural mode and the return of Litter Box mode). There is also a new cat treat collectible that you can collect to unlock persistent stat boosts, special abilities (like a charged swat, a forward dash, and a double jump), and new cat photos (rather than randomly finding them in levels).

Regarding new content, there are brand new tasks (like toppling specific categories of items or finding toys), new gameplay mechanics (moths to catch, robot vacuums to ride, napping), ~30 new cat photos, and some new objects to topple that weren't in the original. Lots of things were updated as well, such as toilet paper unrolling, cat models, general visuals and effects, and even the entire soundtrack (plus one new track for the Pawliday Den level).

Basically, to me if feels like a more refined version of the original game that is more substantial. If you liked the original, Remeowstered is a bunch more of that plus the option to play on some new platforms that you couldn't play the original on. I hope that helps!