The outside is better but need more types of blocks, perhaps another types of wood, and color crystals. And the tree form... this is good but, the same in the Grass gyms: What differentiates a Grass gym to a Bug gym? (yes, I know it's hard). Let me see, in Pokémon Gold/Silver/Crystal the Bug gym was a site with plants, grass and a tree. In Pokémon Black/White, the Bug gym was a circus but like a hive, with honey walls. In Pokémon X/Y, was a big dark tree with cobweb. Maybe dark oak wood wil be better.
Hey Ivanr, I'm helping with Pixelmon in a volunteer capacity to implement gyms into the mod. Reviewing old submissions I feel like this gym has potential and I wanted to see if you were still interested in contributing. I think you were getting closer with this submission so please reach out if you're interested in this or other gyms to the mod.