This is very similar to the old Bubble Bust, but with a path through a "world" instead of the grid to choose the level. Levels must be unlocked one by one--no skipping! The most prominent feature now, though, is the screen to purchase upgrades. You have to bypass it EVERY time you start a level. My other comment it that this needs better directions. On some levels, a Boss appears--I think you have to shoot him multiple times or he messes with you marbles, but I am not sure. He has a meter of some sort under his neck. Also, there are is a timer at the top and the bottom of the screen, both counting down something different, but no indication of what. I think one is related to a lightning bolt, the significance of this is also not explained. Otherwise, gameplay is similar--and a nice time waster.