Yes, it's really mine, but dont worry
Anyway, it's a common made user-error that people dont have a huge hollow block around their level. I quote from the manual:
Q: I don't get any gravity even though I set it via ph_setgravity at the beginning of the main function ?
A: Global physics parameters get reset when a new level is loaded. Thus you should first call level_load, wait 1 frame and then call ph_setgravity to set properties of the new level.
and also:
Q: I've made a small level with only a few objects, and placed a ball into it. When I kick the ball into the air, it seems to hit an invisible barrier at some position.
A: Check the sky box around your level. The ball possibly collides with a side or the top of the sky box. If there is no sky box around your level at all, the level size is automatically limited to an area that contains all the objects. In this case, create a sky box in WED - a hollow cube with sky texture - and make it large enough for the ball to reach the desired height.
Hope that helps, good luck
regards,
