My son is obsessed with board games right now, and my parents bought this game to play while they were babysitting him for the night- they said they played for hours, and my son refused to stop!
The game is basically a clear plastic tube that is set up vertically on a stand so that there are 4 containers at the bottom (1 for each player, although you can play with less than four.) At the top of the tube, there are lots of holes that you fit small plastic sticks (think large colorful toothpicks) into so they criss-cross in all directions inside the tube. After all the pieces are assembled, marbles are poured into the tube on top of the sticks; the sticks hold the marbles in place. Each player pulls out 1 stick on their turn, and each time you rotate the tube to your container; if marbles are able to fit down past the sticks, they fall into your container only. The idea is that you want to have the least amount of marbles to win.
The game is quite fun if you are playing with more people; everyone seems to get into it, waiting to see if they will get any marbles! My son loves the anticipation of seeing how many marbles other players will get. I think it is a good way to teach some strategy for kids, and to be able to see how their actions can cause certain effects.
I think the downside to the game is the set-up. It takes a while to get all the sticks in place, and some of our sticks are starting to bend because they are hard to criss-cross without hitting each other. Also, since it does have marbles, it could definitely be a choking hazard for small children or pets. The recommended age is 5 and up, and I think this is appropriate.
All in all, I think Kerplunk is a fun game, and we enjoy playing it as a family.