I’ve had the weirdest journey with this game. On my first playthrough I thought it was good, I enjoyed it, but it didn’t blow my mind. Since then I’ve replayed it almost annually and every time I find new things which delight me. The central gravity gimmick + the constant introduction, development & combination of new gameplay mechanics + the bonkers level design combine to create the most richly varied and playful 3D platformer ever (I honestly don’t think the sequel matches it on these fronts). Certainly doesn’t hurt that it’s also an aesthetic masterpiece, perhaps as beautiful a game as has ever existed.

One of the best Mario games ever that shows what makes Mario special. Insane fun with a nostalgic vibe that just can’t be matched.

The gameplay is great. Nice controls with gimmicks that don’t even feel like such, with galaxies that are fun to explore and really unique.
The atmosphere in this game is amazing, helped with the ost. As this game’s soundtrack is one of the best, and captures that feeling of being on a space expedition perfectly.
Bosses are fun as hell, and it’s always nice seeing Bowser go from “villain of the week” to a genuine threat.
The best Mario games are ones in which not only do we actually get to see the world of Mario, but said world is filled with so much charm and life, willing to get weird with it. This game is no exception, with Rosalina’s backstory and just exploring different galaxies.

Only issues is that some of the level design is really annoying. Especially the ice fire planet. Also I swear my controls would just give up on me sometimes, which was a pain in the arse.

9.5/10

The movement is stiff and limited compared to 64 and Sunshine, which wouldn't be an issue if the level design was mostly linear challenges like the 2D Marios.

The levels are all over the place. There's clearly a step in the linear direction of Galaxy 2/3D Land/3D World, but many galaxies in 1 are these wide open areas like in 64/Sunshine. These feel so much less satisfying to traverse since the fastest method is usually just running. The long jump feels too floaty, and the spin jump - while useful - halts all momentum. A not insignificant portion of the game is spent not doing platforming, instead gimmicky Wii motion sections which are too simple to be more than a one-time distraction. Some of them are just not that fun at all. I would much rather play Sunshine's lilypad level than do Bubble Blast Galaxy again.

I also really dislike the liberal use of launch stars to travel between areas. They're cool the first few times, but after that they really irritated me. They take too long, often deliberately taking roundabout paths to provide better vistas, and the most you can do during these is collect starbits. It makes replaying missions a chore.

Of course, it's a Mario game, so when Galaxy does stick to linear platforming, it's excellent. Toy Time, Dreadnaught, and Matter Splatter are standouts. The controls are very precise as expected. Really, everything feels and works as it should, I just think the level design doesn't compliment the simplified control scheme most of the game.

Also, the soundtrack is one of the best, if not the best, of the main Super Mario series. I appreciate that, while a live orchestra was used, the compositions still show restraint and aren't, for lack of a better word, generically "epic" orchestra music. There's a lot of variety in texture and instrumentation, and plenty of electronic sounds are layered in to great effect.