game-editor.com

Hi,dudes how can i make a tranplin?You know jump on It
and you go up in the air.

Look the Abuse 2 demo (http://game-editor.com/games/abuse2.zip),
and search for jump in the forum (http://game-editor.com/forum/search.php)

If you want the buldge underneath, like how you would see a Trampolin from the side, why not have a bulge actor at the very bottom of the Z-depth, behind everything else. Use another background actor to mask this off so that the only time the Tramp' bulge shows up is when it goes below the trampolin.

To make it still work at the left or right ends of the trampolin, have the bulge rotate at an angle right about there... hmm... might work... just depends on what frame of animation of the buldge actor you are showing...

On collision with trampoline
yvelocity -= 10;