I went with story mode for my first playthrough. I definitely think it's more challenging than the first game - on story mode it feels like the one easy element is it takes a LOT to actually kill Aloy, but even on story mode it is HARD to defeat some of the enemies. Melee combat has a lot more control, with the ability to land combos and such, but still the enemies (both machines and humans) are much more challenging.

Also some of the puzzles are challenging to an annoying extent. Whether it's a maze or something to find, it feels pretty difficult. Also a bit uneven in terms of the hints - there are times when Aloy or an NPC will chime in with a hint way to quick before you have a chance to find it yourself, and other times when they ain't helping at all lol...

The game is HUGE in terms of all the side quests - it's going to take me a long time to complete all of them.