Boulder Bowl Galaxy

Boulder Bowl Galaxy is a galaxy found in World 2 of Super Mario Galaxy 2. The galaxy features the prominent use of the Rock Mushroom that turns Mario into a solid boulder. Some planets included in the galaxy are made of rocks and soil and steel platforms. Bowling pin-like enemies called Pinheads are found in the galaxy, which the plumber can bowl over by rolling into them in his boulder form. Rollodillo, the boss of this galaxy is fought here. The music in the level is the same as in Spin-Dig Galaxy.

Rock and Rollodillo
To get the Power Star, Mario must first get the Rock Mushroom trapped in a glass cage in the first planet. To do so, he has to defeat the three Octoombas protecting it. After getting the Mushroom, Mario will transform into Rock Mario, which allows him to roll and break things.

To process, the plumber has to use his Rock form to hit the rised bridge and make it fall. Then, he should bowl over the Pinhead and process to the next planet. Here, he has to get to the Launch Star trapped in a glass cage. To do so, he must defeat all the Octoombas found in this planet. When using the Launch Star, he'll find himself on a planet with a Luma who tells him that if he uses the shiny spots on the ground, he'll gain some health. To process, he has to use his Rock Form again and break the giant purple Crystal where the next Launch Star is trapped. After using it, he'll get to a yellow crystal planet with a Midway Point and a Launch Star which blasts him to the boss planet.

After defeating Rollodillo, he'll explode and leave a Power Star which Mario has to get.