Similar to other comments, it's a really well made prototype! Great for a first game, keep it up. A few bugs: building on top of a guy traps him. Surrounding a building with other buildings renders that center building inaccessible and renders its troops/miners useless. I think both of these can be quickly fixed by allowing buildings to be movable.
Font makes it difficult to tell numbers apart; similar to what dogchair said in a different comment. Just a few minor QoL things, but the gameplay loop itself is fun!