The colors are quite vibrant and I can agree that the gaps are also a little too small. I prefer more box-like shapes or open areas when playing because corners are sometimes a problem to get around (like the triangle walls) A lot of the time players make huge boxes in the map for people to fall in. I'd prefer one or two more layers. Besides that, I'm a little confused about the theme and what you're trying to make it look like. The garden maps on TNT run have different builds around it and show different animals, trees, structures, etc. All based around a theme. Cauldron also has a cauldron shape and the blocks are different to create texture. In my opinion, it looks a bit like a mesa biome so maybe you could experiment with that and add some ores here and there and a small oasis in emptier spaces. This is just my opinion and you definitely do not have to listen to me at all!

I'm not a builder but I really enjoy TNT run and these are just my opinions.