Basically to give a sense of accomplishment and to act as a reward thing for playing towny. There could be a menu on the side of the screen with the accomplishments you are close to completing and similar to the /jobs command, you can look at all the achievements to be made. Meeble prizes are given.
Examples (prices scale to achievement level) Also there are endless achievements that can be thought of but here's some:
Towny
Own 1, 4, 12, 16 plots
Create your own town
Create your own nation (or join a nation)
Recruit 10, 20, 50, 100 people into your town.
10, 20, 100 plots in your town.
Create a /pwarp
Have 10, 20, 50, 100 people at your pwarp at the same time.
etc. etc. etc.
Economy
Have 10,000 20,000 100,000 250,000 etc etc. meebles.
Earn x level in jobs
Survivability: when you town reaches a certain tax and your town survives a certain amount of days, you get rewarded.
