The perspective looks uncomfortable with this steep angle.
This reminds me of the shareware Xenno the rogue (link to screenshots page) which allows grabbing the edges of platforms that are too high : it uses a consistant North-East 45° angle, I don't remember if the character is partly hidden when he hugs a left ledge.
Commander Keen also had an isometric perspective, and it worked well, although it wasn't climbing any walls.
Donkey Kong Country had such a distorded perspective
I think one major problem with your picture is that your platform is shown almost from the top. It's nearly Zelda's eagle view with some perspective.
Flatten the floor, increase the angle, be consistent with your stripes. That should do most of the job.