Here is the full list of all 11 ROBLOX achievements worth 1,000 gamerscore. It takes around 2-3 hours to unlock all of the achievements on Xbox One.
Play a Roblox game.
Play 5 different Roblox games.
Play 15 different Roblox games.
Rate 5 Roblox games.
Play a Roblox game for one hour.
Change your avatar's look.
Play Roblox 3 days in a row.
Play Roblox 10 days in a row.
Play Roblox 20 days in a row.
Join an Xbox party and play Roblox.
Play a Roblox game with 3 of your friends!