Well, Jesus sent me this link a few days ago, and since then I have been frequenting this page and looking over it. To be totally honest with you, I know little about your work and can only say that it is a visually interesting cover.
I don't know what the story is so I cannot say that it is an appropriate cover.
There certainly is a really strong home made style to it, deliberate (likely) or not.
However, I think that there are some misinterpreted codes here: 1) the 'look' is DIY
2) The title is "Spiral Bound" or "Top Secret Summer" or both
3) Animal characters in a "wide ruled adventure"?
Hmmm, I think there are too many messages or meanings floating in the cover. Could it be reduced to perhaps a hint of what is awaiting the reader inside? Maybe the Leviathan/ Jonah theme can be the focus with only Spiral Bound as the title? Or the entire Leviathan theme can be excluded with just the cut out characters floating in the murky blue, they are after all looking in the same direction, maybe that could be a focal point.
In all, I can't wait for your book to be released. When it is available on AMAZON please let me know (firstname.lastname@example.org). I am a big fan of comics and loved the little shout out to you by Craig thompson in Carnet De Voyage.