As always with these type of collaboration galleries, I think the heart is in the right place, and I do think this gallery does a lot right in providing a very cool and informative look at some great art from some great artists.
But I'd be lying if I didn't find a lot of annoyances in terms of navigation and presentation with this gallery that really made the process more confusing than it should've been:
*The Back/Next buttons can be really weird because they don't respect history/context. Tons of times I would hit next, expecting to go to the next artist in the country I initially selected from the map, only to go to some completely different artist in a completely different country. Similarly, sometimes I would hit back to go back to an artist I viewed previously, only to end up on another artists page I've never seen. I believe this is because the buttons work off of the assumption that you're moving from the context of the artist list, not the world map or the user's history. Very confusing.
*I really wish there was a way to view the artist's name and info page more readily instead of having to page through all their artwork to get to it. Yes, you'll usually get to their profile eventually, but I don't know why their name flashes for a nano-second and disappears before I can even parse it: it'd be nice if their name was always in the corner (or appears if I hover near a part of the screen, similar to the bottom toolbar) and I could click on it to go to their info page immediately.
*I don't know why the artist buttons when you select a nation don't highlight when you hover over them: I wasn't even sure if I could select an artist specifically because of this.
*I don't know why, maybe it's on my end, but there were a lot of weird instances of flickering text and graphics.
*It's not a huge issue, but I wish it was more easily apparent which countries have content within them. Yes, they get 'pinged' by the rotating sonar animation every now and then, but why not have that alongside a natural highlighting of all of the countries with content? It can just make it frustrating to have to hunt and check every country manually one-by-one to find where everything is.
*What the heck is up with the ordering of the artist list? It seems to be pure random, making it difficult to find someone. Shouldn't it be organized in alphabetical order, or maybe grouped by country?
*Some of the buttons can be confusing: for example, I hit 'Credits' expecting to see the info of the artist I was viewing, only to have it take me to credits for the entire game. Similarly, I was just trying to go back to the world map to select something else by hitting 'Quit', only to have the entire game shut down. Yes, it seems obvious in hindsight, but I hope you can see the logic of how this can be misinterpreted.