Alfred. You are definitely not lacking in imagination and the story seems quirky and interesting enough that I would like to read more.
"I wrote it not really knowing where it was going or who would do what."
Nothing wrong with writing on the go, some of the best ideas come up that way, but it seems you are learning how to write prose on the go as well. Me to. What else are forums like this for but to write stuff and have people tell you everything that needs work with it.
There are usually two main areas to address.
1.Is the story good?
2.Is it well written?
Either one can be great while the other one is crap.
Some people only want advice on one or the other (usually because they are sick and tired of hearing that the other is crap and want to find out how crappy the other one is)
Both have to be great for a story to succeed. You can have the best story in the world, but if you can't write it well, then it fails. The same goes for the other way around, you could be an expert at spelling/grammar, sentence/story structure, etc., but if your story sucks, it fails just as well.
I like your story so far, the image of the well-dressed man with ginormous horns that are so long he has to go to barber to get them trimmed is hook enough for me, but I'm worried that it won't go anywhere and that your creative ideas won't hold water when put to the test in the complete story. For example, why is the island just floating aimlessly? All that's gonna do is cause random dramatic climate changes and possible catastrophic collision with a big chunk of ice or a continent. Wouldn't it be better to use a big anchor? If you don't have a resolution for that yet, no big deal, it's an interesting start, you just better find a way to resolve it well.
The prose definitely needs work. I won't go into specific detail about everything, but the biggest thing that stuck out was excessive use of passive voice and switching back and forth between past and present tense narration.
I'm interested in seeing where your story goes. Pass it along if you want a reader for more pages. Just continue to study writing prose while you work on your story concept also.