I see. I haven't particularly felt constrained by any rules in writing my novel or my poems, but I suppose creating an entirely new format is a good way to suggest from the start that the are no rules at all.

"More like a poem, but an entire story" makes me think of epic poems from history, like Homer's Iliad and Odyssey, but I suppose it's better not to make that association since that comes with something of a definition of its own.

In any case, good luck! If I post any writing that I think fits well as a "micro-novel," I'll use that tag myself.