Hi Mate,
Not bad, nice little setup you have there!
Like others have said it looks a little full. You posted a comment:
"there are no fish in there............. so who want s the swimming space?""
Interesting theory, although i think there is an aethetic impact of "nothing" that you are missing the point of. Like a negative focal point.
It is up to you how you stock your tank so people can only make suggestions and give constructive feedback, but i would also bump what others have said, as an improvement on the nice looking tank you have already created. Maybe try some smaller leaf plants and personally i am not a fan of moss balls full stop (is that what they are??) let alone in a tank so small.
the crypt bottom left is a nice plant, but with it being so far forward it is still large for the tank and thus can not see behind it therfore it is closing the tank in more. If you moved that back left corner it would open all the front of the tank up.
Just suggestions...its personal opinion and i think you have done a good job.
Regards
Chris