I am going to call this very tedious. I've done the first few levels. There’s almost nothing but holding a finger / gun where the zombies are. Nothing changes. Not much sense of peril. My 9yo just joined me, “what’s that game with terrible graphics?” Fair call. m2 iPad Pro. Meh.
It’s okay for a quick fix of an on rails shooter since it’s pretty barren for these kind of games on iOS these days. The old House of the Dead port and especially Doom Resurrection were much better games. Sad that they’re in the mobile graveyard.
My iPhone 4 is a necrappmancer of sorts, because I have those two installed (although I mostly play HODOK on the Wii). Doom Resurrection is pretty much the only game in the franchise that I've played for more than 30 minutes; it's fun enough and the control scheme is simple yet effective.