Stretch

Click on sling's head and drag him to another grab.

Sling

Click on sling's head drag back and release to send him flying.

Drop

Click on sling's head and release to drop.

Bounce

Click on sling's head, drag up, and release to bonce up.

Turn all the grabs green to open the vortex...
Then grab the Vortex to escape and finish the level.