It seems to very much want to exist in the space of making 5E even more of a tactical combat game while also making it way, way simpler. For my money, that's exactly what I'd want out of a game revisiting the "vibes" of 4E, because I just don't have the willpower to slog through even more complexity.
Draw Steel, the 4E "retroclone" Orcus, and Strike! all looked cool to me at first glance, but reading through them I just couldn't push past the complexity level to really get into any of them. Nimble's use of the already-familiar and streamlined 5E rules helps immensely to solve that issue.