Okay. I was a bit confused. I thought that's what you meant at first, but the game you linked doesn't do that. Maybe it's hard to see because the bottom part of the platforms overlap the player.
Anyway, you could create your own jump mechanics that do what you need with events. With varying degrees of difficulty, depending on how you do it. You might even have an easier time trying to create your own platforming movement with Custom Movement behavior, rather than trying to finagle the Platform behavior into doing something it doesn't want to do.
If you do make custom jumping it will likely have to be custom gravity as well. I would try making a variable called "VerticalSpeed". When the player just standing there, VerticalSpeed would be at something like 800. When the player hits the Jump button, it sets VerticalSpeed to, say, -400. Or something. Then, every tick you count VerticalSpeed back up towards 800.
Then you can do an Always event where the player's actual vertical speed is set to the VerticalSpeed variable, and jumping and gravity will be handled for you that way.
This would allow the sticking to the ceiling effect that you want, because even if the player hits a ceiling, whatever remaining negative speed you have left over from the jump will still need to run it's course. So the player will continue to move towards the ceiling until VerticalSpeed is greater than 0, at which point he will start to fall.
That's the theory anyway. Good luck
Thanks for the explanation. I know what you're talking about and how, in theory, it works. I'm going to finish my to do list for the necessary functions first and when there's some time left, I'll look into custom movement behavior.
The game needs to be finished in 1 or 2 weeks, and I still have a lot of work to do so it might get tricky.. Thanks for helping me though!