There is no way you can lose your possessions in the game, which is kinda good since they are worth real money. If you die, you restart at the nearest town and you keep everything. You aren't required to pay anything, you can play completely free, but it will take you a lot longer. I don't play many MMORPGs so I can't compare it but it is somewhat fun if you are new to MMORPGs. From what I have heard, there are much better ones out there, but as far as free ones go, this is probably one of the better ones.
One thing I like is the "land grab" events they have. Its basically an all out war between clans, or "societies", for pieces of land. I was at the first land grab for a while (the whole thing lasted for 12 hours, but I only stayed for 1 hour). If your society wins a piece of land, you control until the next land grab, and you can tax people who mine and hunt on your grounds. I believe you can build apartments and rent them out for money too. There is a lot you can do in the game and they are always updating. Its been a while since I have played so it has probably changed a lot. I'd recommend giving it a try seeing as how it is free. If you do decide to invest, you can invest as much as you want. $1 will get you $10 PED (project entropia dollars).