Even though it seems unstable, it's one of my favourite concepts. I like the risk/reward of taking long versus short rounds. With some polish, better UI and an improved tutorial, I really see this turning into a gem of a game!
For others: if you reload the game, oftentimes the "Endless" button works. Don't go off the grid and just try to stick to WASD. Also, digging for the Golden City is done by clicking Dig (I first thought you ended every turn trying to dig, so I failed my first 5 games haha).