Well, now. Isn't this an adventure for the eyes? Personally speaking, I find psychedelic art out of the subconcious hard to give any specific critical advice; the piece itself looks like a dream

Naturally, it's supposed to be an amalgam of images all sweeping together as an introspective of the mind, and you pull it off very well; it does invoke a sense of madness. As for the content of imagery, I believe its cohesive, with little nooks and crannies to lose yourself within.

I will mention that one must be careful when shoving together a lot of images to not lose a sense of the overall; it's easy to become overwhelmed or cluttered. I feel that the further down the piece we travel, the more focused it becomes. In my opinion the top portion has too many tiny patterns, so it's easy for the eye to breeze over and ignore the intricacies. The recommendation I can offer is to follow what you had done toward the bottom of the page by increasing the differences in values.

This may be my personal taste, but I feel that a bit of contrast can really help with make certain sections pop and create a 3D sensation. I think there should be very dark parts to match very light parts so that it doesn't all blend together in a greyscale mosh.

Other than anatomical tweaks that will come with consistant practice and study, I think that this piece came together fairly well, and if you can focus a bit more when creating this, you'll be pleased with the results.

I look forward to seeing more from you!