What’s explosive about it:
User generated content
Thousands of games
Open-ended game builder
Roblox is a massively multiplayer 3D game environment with of thousands of games that use physics to simulate the real world, and a virtual economy with millions of highly customized characters. Players on Roblox demonstrate incredible creativity limited only by their imagination, using core building components to create their own elaborate online games, social hangouts, and custom virtual items.
Roblox is a virtual playground and brings the popular building-blocks style of play into a MMO. Players can design and create their own worlds and items while interacting with other players. Different games have different goals and elements of fun. Most of them have a little player vs player action while you complete your other goals. Roblox is a browser game type but players must download and install a special Roblox browser.