If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
Drop bombs on the bad monsters with your bubble cannon using the down arrow key. to shoot a bomb on the side press the up arrow when you are facing the desired direction. Watch out for the flying monsters. Collect power ups from your friends but avoid the sticky goo.
Arrow left/right- To move.
Arrow down- To shoot pinky bullets.
Arrow up- To shoot pinky bullets sideways.