the only thing that roblox and blockland have in common is the fact you build with blocks
i suppose i can list a comparison list, though
ROBLOX
-> bricks
-> serious lag
-> impossible to build with others (?)
-> physics
-> browser based (?)
-> servers (or 'places') are hosted on the main ROBLOX website
-> easy-to-use brick generation system
-> massive (but ridiculously kiddy/handicapped) playerbase
-> free to play, but requires monthly payment to receive advanced features
BLOCKLAND
-> bricks
-> very, very little lag
-> building with others is a concept of the game
-> free minigame system, allowing players to play with others in things like deathmatches while others can keep to themselves and build
-> (limited) physics
-> add-on system allowing players to enable and disable add-ons to play with
-> easy-to-comprehend modification system
-> small player base composed of mostly adults, with some children
-> one-time payment
i personally think blockland kicks roblox's sorry ass. but that's just my opinion.