Your goal in Cling is to help Edgar the electric spider to the goal at the end of each level. Use the hooks to guide Edgar there. Watch out for hazards such as falling, poison, and spikes.
After you've beaten all the levels cling has to offer, make your own in the available level editor.
Cursor keys = move Edgar,
[Space] = when held, Edgar will retract his legs and let go of all nearby hooks,
[Esc] = quit the level, or return to the previous menu,
[R] = instant restart of level,
[P] = pause game.