[Jasper_]

I encourage you to try! However, a lot of gameplay and getting movement controls to feel good is difficult and at odds with the goal of "modularized physics", e.g. you might want to apply different amounts of ground friction depending on whether the player is moving, how they're moving, whether they're holding the jump key, and so on.

Ultimately, we're trying to simplify a large simulation of real-world physics and hundreds of controllable muscles and motor responses trained over a lifetime, down to 5 or 6 keyboard inputs. That means you tend to have such inputs doing multiple things, and it's often hard to make separable.

[gmueckl]

I guess, a sufficiently simple exercise would be to write a controller that handles ground movement, jumping with air movement on horizontal ground and moving platforms. Doesn't have to feel good to play, just be reasonably robust. Either handling of slopes and stairs or collisions with dynamic objects can be added for extra credits ;).