A small helicopter, a big map and plenty of other players who want the same ground. Defly.io is a multiplayer IO game about grabbing territory: you place markers as you fly, and once they close off an area, that space becomes yours. Filling in land is also how you level up.
The other pilots are not friendly. You can shoot at them and they will shoot back, and a single hit or a careless flight into enemy territory ends your round. Expanding is therefore a balancing act between greed and safety, because large loops claim more land but keep you exposed for longer.
Progress feeds into upgrades for both your aircraft and your buildings, and the overall aim is to defeat everyone else in the match. Fast arena shooting of the old-school kind is also on the site in Quake 3 Arena.