The idea is neat, and I see lots of potential, but the game lacks some polishing. Controls feel unresponsive, the cancel build key closes fullscreen and doesn't cancel the building unless I click on the button itself, the camera movement with the mouse doesn't really work on fullscreen, and eventually the game breaks, the web build goes completely black and I am unable to progress, that usually happens after I've managed to build my third robot for some odd reason.
Some features of the game should be comunicated to the player, I didn't know I could sell stuff until by pressing right click to drag the screen I accidentally hover a conveyor belt and it got sold, that should be something important to tell the player and you should also make it so that you sell the items when you release right click within a timeframe that starts when you first pressed right click, that would solve accidentally selling stuff when you are dragging the screen.
The visuals are lovely, and they are really good, and I love your cover image and what you did for the web page, like wow, it looks amazing, 10/10 on that.
I also like the gameplay loop, smelt raw materials and process them to assemble robots to defeat the swarm of enemy robots wanting to destroy your factory (I haven't been able to reach that point because game crashes but I assume that's the idea judging by the gifs), it's a neat gameplay idea, it has what I'd expect of a game of this genre, gather resources, build up and face a challenge at the end, and rinse and repeat while also upping difficulty.
Anyyways, I apologize for the rant and for not being able to fully experience the game, but I hope that you plan on working on this one after the jam is over, I can see it becoming a really neat and fun game.