I’m up to 45 stars now in Super Mario Galaxy, and it continues to be fresh and exciting with every new galaxy. I think I only need 60 stars to beat the game, but I’ll probably continue collecting as many as possible, so who knows how many I’ll have at the end.
I finally got to try out two other powerups tonight: the ice flower, and the Boo mushroom. The ice flower lets you run on top of water by freezing it, and it took me a couple minutes before I realized you could wall-jump up waterfalls that are close together with it. The Boo mushroom turns you into a ghost, but all it’s been used for so far is to let you go through some bars. 99% of the time you’re still just plain old Mario, without any powerups.
I also ran across a comet that I wasn’t able to finish for the first time — it only lets you have one health point in a fairly long boss fight against Bouldergeist. It’s supposedly one of the harder comets, but I think it’ll be doable — I only lost one health point when I fought him normally, and came close in the couple attempts I made at the comet. It’ll just take some persistence.