I need to make kind of "tips for the beginner composer",
but I want to use the time I have left to try and finish my piece.
Anyway the tips I keep giving is- longer isn't necessarily better.
I didn't have anything I could stick to.
No repeating theme I noticed.
Sometimes it's fine, I tend to do that too.
You didn't change the dynamics, and that bothered me.
You can't keep playing loud all the time.
Loud all the time is not loud.
That leads us to the other tip, your good choice:
you wrote for one instrument.
You limited yourself.
And that's so great- that's the other tip I usually give to amateur composers
(not to worry, I am one myself but I have a few years of experience).
When you have one instrument you have to use your other tools.
Modulation, dynamics, tempo, rhythm etc.
Challenge: try and limit yourself even more.
Write a piece for piano only using F E and Bb.
Or any other combination.
Try to have a repeated theme.
Remember that longer doesn't mean better.
I hope I wasn't too hard on you,
now I got to go wash the dishes or my father would kill me.
Hope that was helpful,
bye