The first miku has simple attacks mixed with player-aimed attacks and disappearing blocks that is an insta-kill which forces you to memorize it. The song is a little long, but the attacks are very simple to learn so it's not bad. Next avoidance I beated was very short, (Steins;Gate Opening) but consists of many insta-kill attacks that seems very hard and can't be easily dodged. But all the attacks are fixed or player-aimed, so it's alright I guess. This one is very hard compared to the first miku, so a lot of patience is required to beat this. (The first 2 avoidances has 0 random attacks.)
The 3rd one I beated was Pop'n Music, which the music was great at my taste. This time there are pattern attacks, random attacks, player-aimed attacks, all the basic attacks are here. The fixed attacks are simple to dodge since there are some save places, but the avoidance makes you to memorize that save places, and added with simple random attacks, it becomes a pretty good avoidance. The 4th one was horror-themed gumi music, and it is SUPER well made. The music is great, forces you to move to different locations (especially the spotlight section. This part was SO great.) and the patterns are almost consists of player-aimed and fixed ones. The fixed patterns seems hard to dodge at first glance, but once you know how to do it, it becomes incredibly easy. If you have built your skills up before this one, you can clear this avoidance in no time. (spend 5 hours beating up to this point.)
And the last miku is the true heart of this game. The patterns are now consists of beautiful player-aimed attacks and many random attacks that is SUPER RNG that can't be easily dodged in first try. Grinding this boss was very fun since I loved the music, but can block many players from clearing this game. (The final attack is an insta-kill if you don't know how to dodge it, so I recommend you should watch a video of it before challenging this boss. Otherwise it can cause mental breakdown.) Beating the final avoidance requires luck and a lot of patience and skills so if you managed to beat this, you will now realize that your avoidance skill is highly improved. (spend 10 hours.)
It's obvious that doruppi spend a lot of time making this game, since almost all of the tile sets in this game are original, and the difficulty curve is close to flawless. (except the Steins;Gate Opening which I beated in 2nd.) The last miku is very hard compared to the rest of the avoidance, but the visuals and the production value and the music makes this game highly worth it.
The game introduces you of teaching basic avoidance attacks that gradually becames harder. (fixed attacks -> fixed patterns and player-aimed -> random) This game is VERY old (2011 December), but the gameplay is magnificent and holds up very well to this day. The rating was going to be 8, but added 1 point more since it's very old. Highly recommended to any levels of avoidance players, especially if you are going to improve your avoidance skills.