Beyond the difficulty settings and choice of characters, Assassin's Creed: Odyssey gives players two choices at the start of the game. You can either have the traditional questing experience, or you can try "Exploration Mode".
It's a mode that removes most of the traditional guide markers and waypoints. In practice, it sounds like it removes a lot of the handholding from the game—but in reality, you're still being lead most of the way.
The game doesn't give you a visual description of the markers beforehand. But to give you a general idea, here's a shot of Origins from Kirk's review last year, with the general objective outlines, HUD icons and what you'd expect during general gameplay:
In Odyssey, this is what you'll see in exploration mode.
The largest difference you'll note is the difference in objective descriptions. Rather than explicit directions, you'll get more guided advice. It's been described as a hints-based system. Objectives will tell you that NPCs or quest areas will be in a cardinal direction or the general vicinity of something else. "Rumour has it he docked in the centre of the Pronnoi Peninsula," one quest objective reads.
The minimalist nature does remove a lot of clutter from the UI, mind you, which indirectly serves the game well—at least visually. But Breath of the Wild, this ain't.
Where this unravels slightly is Odyssey's tendency to tell you just a little too much. When you get within range—about 300 or 400 metres—the game will give you a prompt. It's impossible to miss:
And when you bring Ikaros (the new Senu) up, the game's very upfront about where you need to look.
Even when you're roaming around the world, when the UI is displaying the least, you're still given at least one or two ideas of where to head. The objective text is precise enough that you're never struggling at any point.
It's so guided that I'd argue you don't really do that much exploring in Odyssey at all. It's a bit like taking away the dotted line and the zone indicator from The Witcher 3 radar, but the game tells you in text form the general direction you need to go, and when you get close enough the zone indicator pops back up.
I bring all of this up, not so much as a criticism but more for setting expectations. When someone tells you that you'll have to investigate a world to discover clues and objects, people wouldn't be forgiven for thinking of games like Fallout: New Vegas, Hollow Knight or maybe even something like Bloodborne. You go a certain way because that's all that's available to you, and over time you'll either unlock the skills you need to wander into more areas, or you'll find journals or notes or whatever else it may be that indicates (but doesn't expressly outline) the next step in your journey.
Odyssey isn't that. The risk of you actually getting lost is pretty minimal. And that's not a bad thing! It helps visually, and keeps the player becomes a little more involved in between quests. But if you're hearing comparisons between Odyssey and Breath of the Wild, and wondering how much time of Odyssey's supposed gargantuan playtime you'll spend lost, don't fret. This is still an open-world Ubisoft game, after all.