Enjoyable.

These are all OK: Did you enjoy it? Was it enjoyable? Was it a joyful experience?

No, I do not think so. "ful" is not used with verbs if memory serves. It is a suffics which indicates full statement, full form of something - joyful is from word joy, so full with joy and beautiful from beauty - full with beauty. But enjoy is not used like a noun and we cannot produce adjective by adding "ful". noun of enjoy is joy and joyful is better to say.