Very cool concept!! I love the spider walking, the sounds it makes with each step, and grass/wind animations are a nice atmospheric touch. Super cool for your first 3D game. Definitely looks like a successful learning experience! I can see a lot of potential here.
I know it's an early prototype, but here are my initial feelings while playing: Love walking around! Really satisfying sound design. I didn't like how I had to wait for it to come to a complete stop to start harvesting, and would like pressing E to automatically brake and go straight into it so it feels more responsive. There's no real consequence to houses and turrets falling off right now, but I could see that being frustrating in a more complete version. Maybe the spider could have an additional arm for recovering lost houses that picks them up and puts them back? I could see it being another layer if there are enemies that impact you and make you drop stuff, or wind gusts which blow them away and you have to go and pick them back up. But i'm not totally certain about the concept of dropping them to begin with, cus it took a while to harvest and build them so it really feels bad to lose them quite easily. The walking city-building itself is SUPER cool though. I REALLY like that aspect of the concept and think it has a ton of potential. I could see having enemies to fight like a moving tower defense game would be super fun. The music choice was really nice — I had it playing on loop the whole time typing this comment.
Very well done prototype and grats on your first 3D game! Excellent work!