I like it!
Is the tank to be viewed from both sides or just one? If it's both, I would personally move the vallis and sword over to the left-hand side, add the spider wood to that side too, and move the filter and heater over to that side, space permitting.
I'd have the smaller plants around the bottom of the wood and perhaps rocks. I'd probably add more crypts too, but they're just my go-to species. Dwarf hairgrass will look lovely in there.
Honestly though, it's your tank and what I'd do doesn't matter
even if you did absolutely nothing else to it, I think it's nice now and will be even nicer once the plants have grown in a bit.
Oh and on heaters, I'd probably keep one in there to ensure temps stay fairly stable, even if it's set much lower than you would suit tropical fish. It would also help avoid the dreaded "crypt melt" too. Then again, it depends on the ambient temperature in your home/work at night - I live in a stone flat built in the early 1800s with drafty windows, so it's probably much cooler at night than a temp-controlled modern building.
Edited to add: If the tank's only meant to be viewed from the side shown, then I really like the small hill on the right-hand side. A wall of vallis at the back, with bushes of mixed plants and wood on either side and an emptier plain in the middle (maybe with a hairgrass carpet?) would look great too.