Uppy

Uppy is a free co-operative multiplayer browser game where everyone shares a single balloon for up to 100 players at a time. Tap to push it up — but you can only tap once every few seconds, and the cooldown gets longer the more players are in the lobby. The only way to keep the balloon aloft is to spread your taps across the crowd and work together. 

There's no download, no install, and no signup to start. Open the page, pick a nickname, and you're matched into a live lobby with strangers around the world. Invite a friend with a single link to play in the same lobby. One shared balloon. 

One shared score. Truly co-op — no competition, just teamwork.