I was joking when I said (maybe to myself, maybe somewhere around here, hell if I can remember these days) stuff about more near-future game development largely looking like someone shiftily looked around and then filched the design of those custom maps. More SC2 by way of lesser clunkiness, but.
Engine et al actually being built for it has more or less always been one of the major fiddly bits of making those things, and it's not even remotely like the general design is unenjoyable or anything, especially since there's very little else on the market that really leans on fusing RTS and city building mechanics. The thing's a friggin' civ-style WC3/SC2 custom map, right down to upgrading the residential income buildings.
Took a second to watch some gameplay of this.