This is a pay to win game, it's impossible to do anything without wasting money on coins, 99% of the servers are empty, and it is a horrible game that should be removed.
Currently there is an in-game achievement for beating the Ender Dragon once. After that, you just get an Ender Dragon eggs. We might do something with those for a future update. As far as Kongregate achievements, they've told us they don't want to do it for GrindCraft.
 "Void Vikings"){kind=icon}
 "Ultimate first person shooter."){kind=icon}
 "Deadly Ascension"){kind=icon}
 "Blockade3D"){kind=icon}
 "City Siege"){kind=icon}
 "Learn to Fly 2"){kind=icon}
 "Super Mario 63"){kind=icon}
 "Super Villainy"){kind=icon}
 "GrindCraft"){kind=icon}
 "Bowmaster Winter Storm"){kind=icon}
Currently there is an in-game achievement for beating the Ender Dragon once. After that, you just get an Ender Dragon eggs. We might do something with those for a future update. As far as Kongregate achievements, they've told us they don't want to do it for GrindCraft.