Is the ocarina easy to play?
'Is the ocarina easy to play?' is not a straightforward question to answer. It may or may not be depending on your past experience. The biggest challenge of playing ocarinas is often their unstable pitch, so if you already play wind instruments and have a good sense of relative pitch, then you should find the ocarina quite easy to play.
Frequently, those asking this question are new to music, and are attracted to the ocarina as it looks simple. If that is you, these intuitions mostly hold true, but don't expect to become an awesome player overnight. There's more to playing musically than knowing a fingering system; you also need a general understanding of music and a sense of musicality. Developing those skills takes time on any instrument.
The fact of the matter is that all instruments are challenging in their own ways. The ocarina isn't as easy to play as it first appears, but don't let that influence your decision to learn to play it. If you've chosen the ocarina because you enjoy its sound and you're determined to play it yourself, you've chosen it for the right reasons. The same goes for any instrument: play it not because it looks easy or difficult but because you enjoy it.
It is also important to note that how you approach learning an instrument has a big impact on the progress you make. As ocarinas look simple, one may assume that they don't require technique. Unfortunately this is not the case as many techniques are not intuitive. Approaching playing in this way can leave you with little to show for your effort.
I recommend reading the page 'How to approach music as a beginner' and my article series 'Learning to play the ocarina'. Don't be tempted to take shortcuts. Ocarina tabs especially are a double edged sword; while they can help you to get started, you should not become comfortable with them, as they will quickly hold you back.