(1) and (4) could probably be done with a behavior that allows to toggle with an alternative configuration. This behavior seems to be a good case where the same behavior could needed multiple times on the same object.
(2) It could be interesting to also have a vertical dashing (for instance, to smash enemies on the ground like in Dead Cells) or a dashing toward a position (to do things like the homing attack of modern Sonic games)
I think that a platformer bounce behavior could be useful to bounce off an enemies or spring. I guess, it could be done with a jump that has an alternative configuration.
(5) An object that can be moved in a platformer can almost be done by adding both the character and platform behaviors. But it’s not easy to push the object with a character because the character looses its speed when it collides a platform. It would need:
a new setting to keep the character speed at collision (or the extension could save it and put it back)
an action to change the current speed on X axis of the object to set it to the character speed (and eventually reduce the speed of the character to feel the weight).
Platformers that change the gravity will probably have other very custom rules so they will probably need a custom platformer system build on top of a physics engine.
In case a gravity to North, it would mean to choose between top/bottom, positive/negative and greater/lower everywhere in the code of Platformer. So, it will probably never happen, but it can be workaround by having a copy of the level rotated at 180° and switch the character from one to another when the gravity toggle and rotate the camera too.
Wall running, seems to be something possible, but it would need a lot of changes:
the jump is not necessarily in the same direction as gravity
a character on the floor can slide with gravity
and probably all sort of other tricky cases
The platformer extension could give an option to follow a floor with a constant speed (it’s currently constant on the speed X)
Greetings, I’m very interested in your make unit movements like in some tactical games with GDevelop. I’d like to chat with you, but I can’t find a way to contact you. It is interesting how to complete the move and transfer it to the enemy and the attack of the units itself. I’m a beginner in gamedev))