Axis + S. Italy/Romano:
Italy/Feliciano Vargas: Feli’s gonna be the guy who has no idea what he’s doing, but still has a good time. Give him 10 minutes, he’ll be blowing that gas station up and sacrificing humans to the Goat Demon Lord in no time, laughing his adorable head off.
Germany/Ludwig: He doesn’t know what he’s doing, what this game is, why he’s playing it or where it even came from. His reaction would be similar to that of a confused donkey (Because that’s a thing.).
Japan/Honda Kiku: Kiku’s just confused. He’s just staring at the screen dumbfounded as to what you even accomplish in this game. Regardless, Kiku will find any and every easter egg in this game.
S. Italy/Romano/Lovino Vargas: Lovi’s swearing half the time, whilst trying to figure what in the name of God all mighty he should be doing. Exclaiming “What the fuck is this shit?” every 5 to 10 minutes or he might just get irritated and uninstall the game. Actually, he’d probably do both.
Allies + Canada:
England/Arthur Kirkland: Arthur hasn’t the slightest clue what this game is, but fuck you to the person who convinced him to play it in the first place. Arthur would probably react very similar to Lovi, swearing at the game and then getting irritated to the point where he just uninstalls the dumb thing.
America/Alfred F. Jones: Alfred, out of everyone, enjoys this game the most. He’ll probably just cause mass destruction in the game, add some mods, fool around for a long time. He will uncover every secret this game has to offer.
France/Francis Bonnefoy: Francis doesn’t like modern technology, not a bit. So sitting him down to play this game would probably go something along the lines of giving a child from this generation a cell phone from the 70′s.
Russia/Ivan Braginski: Ivan will find anything that blows up and somehow crash the game from falling/flying off the map. Ivan is the master at game breaking. He’d probably swear under his breath in frustration because he has no idea how these controls work.
China/Yao Wang: Yao doesn’t like modern technology nor does he know how it even works. He doesn’t want to know how it works either. Somehow convinced to play this, crash the game, exclaim modern technology sucks and then go meditate in the garden. Curse modern technology
Canada/Mathew Williams: Mathew, out of everyone, probably plays this game the best. I mean, he’d probably be confused to what the point of this game is, but he’d still find every nook and cranny of this game and simultaneously laugh his butt off.