To be entertained a good film has to engage us and this is done with how well the film maker can bring us into their visual creation. How well they use the tools of film making determines their success.
Being provided with amusement or enjoyment is entertainment for us. We are entertained by film in many ways and not always the same way for each person. That is why we have different genres of film to enjoy.
We do alot of post production for independent film artist. I have seen many films that come in that are technically great but don't provide the entertaining discovery of a story. This can be as simple as the sound effects are great, but are used in a way that is so predictable that they don't lend to the movement of the mood or story.
In my opinion a good film should be a journey.
Don’t hit them over the head with the effects, sound and a story that is so layed out that there no engagement from the viewer. Let your audience discover as they watch, created some curiosity that promotes interest.
Here is a quote from independent French director and musician Woodkid’s (aka Yoann Lemoine) approach to music videos.
“I create these stories with missing pieces. Missing pieces are very interesting because then people wanna fill them. People are afraid of emptiness and they wanna fill those gaps…. That’s exactly what I want to do with my art. I want people to think about what they see and wonder if what they see is real. If what they see has a meaning.”
Here is one of his video's with 24 million views!