2v2.io takes Fortnite's build-and-shoot loop and makes it a team sport. You and a partner drop into a small arena against two opponents, with the same four building pieces — wall, ramp, floor, cone — and a handful of weapons. Whoever gets height and cover first usually wins the fight, so the game becomes a race to build.
It runs entirely in the browser with no account, matches take a minute or two, and the building is close enough to Fortnite's that practice carries between them. There's a free-build practice mode for drilling edits without anyone shooting at you.
No. Pick a name and play; everything that affects gameplay is free.
It borrows the same four build pieces and editing, in a much smaller browser game focused on short team fights. Players use it to practise building.
Yes — it runs in the browser with nothing to install. It needs a live connection for matches, and a mouse helps a lot.