There's nothing stopping you doing so despite of the state of Teraurge (Luckily they can't patent ideas and Meandraco is not Nintendo or WB). The more the merrier
The "Specialness" comes from Meandraco's Artistic Vision, and I don't think it's something that can be replicated.
Coding and Engineering is the ground work and it can solidify a project greatly, what really matters (To audiences) is the creativity on top of that (sadly).
But I don't think you need to be a "spiritual successor" (IMO that's more of a Marketing Term), Every game is an iteration, you took inspiration and do your own spin on it.
The only thing stopping me is my current work load, I am completely swamped so it's hard to get my foot in the door with something like this.
The vision that Meandraco has is done so well, the world just feels alive and teeming with so much lore that it's really more of a worldbuilding project than a game project, it's something you need to take so mcuh time to consider to even get remotely good. I think the creativity aspect of this game is in its gameplay with how free and open it is to do what you want, which is what I'd like to replicate if I were to make something of my own (plus of course the terato stuff in the game)
I was thinking of making a solid mod for the game at some point with some homebrew creatures, but again life got in the way and not being able to create new locations is quite limiting. I was working with someone way back to make a subni expansion mod together but that fell apart when I stopped hearing back from them
Now that I think about it, I have a completely unrelated worldbuilding side project that could probably be tweaked and retrofitted to be a great setting for a game like this, set on a world with very low gravity since I've already designed a lot of creatures for that world. This might be a great starting point for me
