Everything looks good as in planting. IMO I would trade places of the two rocks on the left, the larger one to the back. Then I would increase the slope in the back, maybe to the corners or off-centered.
Keep in mind those Blyxa will grow bigger, so I would place the ones in the front to the back and keep the Alternanthera Reineckii 'mini' in the mid-ground.
Other than that, it looks pretty cool! I like the sunset effect too.