Oh, but nowhere that I can see in the controls section does it say that you can press spacebar to 'expand' you golf ball character to hit the goblins.
Glad you enjoyed it! I added one longer boss-like level as a sort of test in a new version recently. I will be looking at taking the game concept further in the future too if I get the chance. About the expanding big ball, I was intending to take it out completely as I was looking at several power-ups initially but didn't fully design the system, but left it in there semi-hidden as sort of a little fun ability.