Amazing.
I love this game quite a lot. Particularly I got it because of Rimi and Kurisu being playable ingame, as I had played the newer Phantom Breaker: Battle Grounds and enjoyed that a lot. However, I was blown away by how much I had to LEARN to play this game.
It's tough at first, hard even (I was playing on Normal difficulty). There's little English text to explain how to play but if you've played Battle Grounds with a gamepad, the controls are the same except for line jumping. Playing through Situation Mode (you can look up the requirements for progressing online in English) teaches you how to play the game very effectively.