While it is a fun and interesting game at first, Bloom Blox can easily get boring quick.
There are a few core gameplay methods in Boom Blox. The first has you strategically throwing (which consists of pointing and clicking A to lock your position then a throwing motion) balls/bombs into a structure in order to knock down special blocks. Others include hitting certain types of bricks to make them disappear, cause a chain reaction, or blow up. Some games are even like jenga where you have to remove certain blox. The base of all these game types is pretty much just to knock stuff down. It's good simple fun and can keep you entertained for a bit.
That is until you play most of what the game has to offer. Yes there are a lot of puzzles to play, but they don't differ much. The ones where you make stuff explode or just generally knock things down are fun, but there are other game types that just aren't. These include ones where you have to make a path for people to walk on, shooting gallery type things where you have to defend 5 people, or escort missions where you have to move blocks and keep enemies at bay. None of these are as fun as just generally knocking things down.
Lame things aside, there are more positives about the game. For one, the multiplayer is simple and fun. There is co op and competitive gameplay and it is a sure shot to keep you and your friends entertained. Also there is a stage editor where you can create your own stages and share them via WiFi. You can either create fairly simple stages or pee wee herman breakfast machine complicated stages.
Overall, Boom Blox is a good game. If you don't usually play with multiple people on you're Wii, give it a rent. If you are looking for another game to play with friends, rent it and then see if you want to buy, you could have a blast, you could not. It depends on your taste really.