From an on lookers point of view (meaning i bought it for my Girl friend and i just watched her play it)
So you start off the game with a small plot of land which you have to clean up by whacking things with a spade. Basically this is the only violence you will get in the game so people who are more into games such as GTA should probably step away now.
Once you have made your patch of land all pretty and nice you ill get all sorts of species of pinata come and look round. That amount of different types is immense ranging from small bugs to huge animals like elephants. The designers have put a lot into designing the animals and just waiting to see what pops up next is quite fun.
You buy all sorts of things at the shops which come at a steady pace as you progress through the game. But it wont be to long until you get a good selection of shops and things you can buy. My only gripe is the general store lady as she gets pretty annoying after a while. We wander if we could hit her with a spade but it seems we couldn't.
The level up system works well and you do get some considerably good upgrades to your spade and other things. The challenge is to get the pinata's to (as they so innocently call it) romance dance! making more small baby pinatas. Once you get the pinatas in your garden to become resident by meeting their needs you then have to get them to be ready to romance by meeting to more of their needs. Then once those parts are over you select the 2 pinatas you want (they have to be the same species so no mutant pinatas I'm affraid) it will take you into a mini game where you direct one pinata to the other through a maze dodging obstacles and collection coins. Bit crazy but it breaks up the game well.
All in all viva pinata can kill a lot of time. Even though it isn't my type of game i can defiantly see a lot of potential in it for many gamers out there