A Gummy's Life is a really fun multiplayer game that can be played with local players and online. It's now left Early Access with a major update.
I've had quite a lot of fun with this, especially with my Son who adores it because it's completely silly. One thing that wasn't too great was the movement system, which they've actually overhauled as part of the 1.0 update. Movement seems smoother, more responsive and you have a better amount of control with it now too making it an even better experience.
They also added more feedback when you're hit, an improved netcode for online play, the ability to invite friends from any region into a private game, improved AI behaviour, performance improvements and more.
You can play with up to 16 people in local multiplayer or 8 online, the gameplay is easy enough for a six year old to pickup yet there's room for people to become really good at it, plenty of maps and game modes, some silly physics and more. I absolutely recommend it if you like some utterly mindless fun.
Find it on Steam.