Sketch - "L'Attente" for piano [Update 04/19 : Complete version]

Is this a work in progress piece? Because I think you should do the long version of this. I like the ideas you have but for example bars 17 to 20 feels odd to me, is like too soon for that, I was expecting the melody to start again.

 

Try AABA form.

Repeat bar 5-16 and then go to your current bar 17 as B.
And then end with 5-16 again.

You can even do direct 1 to 1 repetitions of 5-16.
Look for example at Beethoven's sonatas. They are all structured like that.

After that it should feel more like a complete piece.

And when you have done this, you can try to add a little variation (just a little) at the last A.

 

First of all: I like the vibe of your piece. sounds great.

BUT:
The repetition of the A after the B is really essential. Without it your piece just goes somewhere but never really concludes. That can be intentional of course, but it's really uncommon and unsatisfying for the listener.

Imagine for example the first Back to the Future movie, without the scenes where Marty is back in 1985. The movie just ends after Doc managed to send Marty back home. It would be weird and unsatifying with loose ends. Set ups which never get a punchline.

I would suggest to literaly copy and paste your first A and repeat it (That's fine to do, don't try to overcomplicate things. The closer the first two As are, the better!). Then go to your B and conclude with your A'

 

This piece sound very beautiful.
Something I noticed was that the ending seems kinda off. (the last 3-4 bars.) But that may just be me.
Maybe also try to experiement with modulation so instead of repeating the same idea in the same key then repeat it in an other key to create more interest in the piece.
But it was a very nice piece.
Good job.

 

Feels off to me as well, but I think it would be solved repeating A section as Michael suggested.
B section now fits much more better in my opinion. Nice piece Antoine.