I like to describe this as Sandbox Parkour!
Not in an open world kind of way, but they way each level is treated! You can run or jumps on almost anything you see! Often multiple ways to get to your goal. And there are a lot, I think close to 70 levels? I haven't finished all of them.
For each level you can get Bronze, Silver, Gold or Ultima medal, but there are also leaderboards, and you can play against the ghost of any player, or you own ghost.

Apart from individual levels, there is a hub world for each of the 4 unique areas. These are big open areas that contain puzzles, secrets and token for you to collect (tokens unlock skins), as well as a way to access each level (You can also do so from level select menu for a quick way around).

I bought this game in Early access around 2020, and the thing that immedietly got me hooked was the feel of the game, it is very responsive and well animated. I never get bored of wallrunning XD
The development was on hiatus for a while but they came back strong and made a lot of improvements, AND, a Level creator!

It is called Create Mode and it some of the most fun I've had creating something in a video game!
It is super intuitive and you can create almost any level you want. And then you can play it and share it with everyone.
Around half of my time in this game I've spent in create mode, I just find it so addicting XD

As a lover of Parkour games, I can 100% recommend this.

I spent 25 hours playing the demo, and I was completely hooked from the start. The gameplay and overall atmosphere are absolutely fantastic. I found myself getting lost in the game for hours at a time, and after such an enjoyable experience, I knew I had to get the full version. This is definitely one of the best games I’ve played in a long time.

If you like Trackmania, give it a try! You'll feel right at home as you jump, slide, and zoom through the levels.