I'm ~15 hours into 13 Sentinels. The combat side is alright. Kinda easy (I turned the difficulty up right away), and visually you can tell it wasn't what they spent their money on. Like everything else in the game the combat missions don't seem to be chronological, either, so I'm not sure when they're even taking place yet.
Story side is definitely the draw. For how much it jumps around I'll say it's never felt like it has gone off the rails for me yet. There's also thankfully a giant timeline in the archive mode, and whenever you see an event happen it slots it into the timeline chronologically, so you can always check back there and kinda start piecing sequences together.
Also: references. So far I've seen E.T., Terminator, Evangelion, and Godzilla, at least. It gets edited out of the English subtitles but the Japanese voice work also explicitly name drops H. G. Wells at one point. Also there's a talking cat for some reason.