A lot of criticism about this game isn't very good.
"Every gamemode is stolen!" The way you engage with the primary
Elite Beat Agents gamemode is completely different from the original DS games, both in the fact that you're playing with a peripheral that controls a cursor on a screen instead of tapping on the screen itself and the fact that osu! is a game for complete tryhards like most rhythm game simulators, unlike the original games' focus on the silly narratives told between gameplay. Also, stealing game mechanics has literally been a rhythm game staple since the genre's inception, even in games made by actual companies instead of some Australian guy.
"They don't even license the music!" This argument comes off to me as a way for elitists to stake their dislike for the game in some ethical foundation. That being said, copyright law sucks and this is awesome. By the way, osu! is the only rhythm game simulator that I've ever seen criticized for this. Try saying this about
StepMania and see what reaction you get.
For about 6 years of my life, the aim-based gameplay of osu! was the most fun thing I had ever played. If you like the flow state and gradual improvement aspects of other games with high skillcaps, then you'll like this. That being said, the game disagrees with me on how to play it properly, so it was usually a cycle of playing for about a year, improving and seeing no reward from the game, deciding to finally play how it wants me to, cutting my rank in half, burning out, not playing for 3 months, and repeating the cycle.
The worst aspect of osu! in my opinion is its combo scoring system. If you wanted to judge how well a map was played (not including accuracy), the intuitive solution is to judge how many notes were missed, like most rhythm games. Instead, osu! judges the merit of a play almost entirely by how long you can go without missing. This also means full combos are the only real way to gain ranks or place high on leaderboards. I'm not opposed to having to go a long time without making a mistake in a video game—I've completed every level deathless in
Celeste—but in my opinion, this system feels terrible for this game. Notes in osu! don't have as much variety as obstacles in platformers. And unlike a game like
Clone Hero, another combo-based game where charts have distinct sections and require a variety of different methods to hit, the way you approach each section in osu! is mostly the same. Gaining muscle memory actually makes you worse at the map in what the community calls "mindblocking." You can't improve at a map during attempts: If anything, you get worse. Also, this makes any play that's not an FC feel totally random (missing once in the middle of a map destroys any chance of a high score) and makes any play with over 10 misses totally worthless.
The game, or at least the stable client, is full of questionable design decisions. In DDR terms, the game has no "Marvelous" and skips straight to "Perfect" and "Great". The 300 and 100 judgements are blue and green to reflect this. Where in other games a good accuracy might be marked by a 6:1 M:P ratio, good accuracy in osu! is marked by not hitting a lot of 100s, which is usually around 90:1. This makes the accuracy skillcap feel pretty low and sometimes random. You have three choices for rate changing a map without an external program: 0.75x, 1x, or 1.5x. Anyone who's played other rhythm games with rate changes knows that these values are extreme, and that rates like 1.1x or 1.2x are much more useful. Also, the concept of "notelock" is one of the biggest fumbles in any popular rhythm game. On the upside, the last two things I mentioned are changing in the lazer client, but there are no plans to change accuracy.
The thing that makes osu! worthwhile for me, other than the gameplay, is the level design. Hot take: osu! is the most expressive rhythm game for pure level design (that I've seen). NotITG obviously surpasses it in general design due to its visual capabilities, but in terms of ways to manipulate limited gameplay elements to create interesting playing experiences, I don't think it gets much better than this. The addition of the 2D plane takes creative possibilities to the next level, with concepts like cursor momentum and visual choices becoming essential to consider. The fact that osu! has a big community and was released in 2007 also means that people have pushed these mechanics really far. I genuinely believe that mapping osu!standard is an awesome form of creative expression that everyone interested in rhythm games should try. It will definitely destroy your ability to listen to music without hallucinating hitobjects, though.
My experiences with the playing community have been...not great. YouTube content is a hellscape that hasn't seen a good video since pishifat stopped uploading, and the whole community seems to have this "pull yourself up by your bootstraps" mentality in terms of choice of peripheral (mouse vs tablet) and the topic of improvement stagnating. The community also has a weird superiority complex with mods similar to your choice of character in fighting games, but even more so. Seriously, it's not a crime to put Hidden on a play, guys. Also, for a game riddled with pedophile jokes from outsiders due to its connection to the anime community, you would think that Hard Rock pedophile jokes wouldn't be as popular as they are. The mapping community is better but they're kinda always fighting. If you're a mapper, stay off of Twitter unless you like internet arguments. And if you're a mapper and on this website, stay off of OMDB, at least until the userbase becomes less pretentious.
I think it says something about how fun this game's gameplay and mapping are that despite all of this, I still think this game is a 6/10.