That's really impressive! I haven't even come close to developing a game since I played with the old school Game Maker back in high school, but pathfinding seems like a very intriguing challenge. You've got a new YouTube sub. :)
What's the tech stack you're using for the game? I'm not really familiar with how games are typically made these days other than that it seems like a lot of people are using Unity.
I'm using C++, SFML (graphics framework), and SQLite (for data storage/saves). Game & engine is developed from the ground up.
A lot of people choose existing engines for their games. I definitely would if I were to go 3D.
With 2D grid based games, it's not too difficult to get an engine up and running. It took me around 6 weeks IIRC (no physics or networking code though) to have basic tile placement functionality and outputting the game world to the screen.
What's the tech stack you're using for the game? I'm not really familiar with how games are typically made these days other than that it seems like a lot of people are using Unity.