How to give the player gravity without platform behaviour?

I am working on an endless runner, everything (except the player) moves from right to left. The player needs to be able to have gravity, so he can fall into holes. But adding the platform behaviour messes with the player position, when all I really need is gravity (and no movement whatsoever).

Any other way of achieving that? Disabling platform behaviour and enabling it whenever the player is supposed to fall is probably not a very smart solution.

The easiest way is to add Bullet behavior, and set angle of motion to 90 degrees. It will constantly pull the player down. But it may interfere with other events in your game, so you might need to make some changes.

Or simply set player Y to (self.y+100*dt) on every tick, where 100 is gravity speed.

If you only need gravity, then platform behavior may be an overkill. You can control collisions with the ground with events. Say, when object is overlapping ground, set bullet behavior disabled.