This is Pop'n Music 15 Adventure, a music game similar to Beatmania where the objective is to keep a certain percentage of quality in skill. While the peak of the difficulty is easier than Beatmania, it's learning curve is steeper than it with nine large buttons over seven keys and a scratch record.
My series of videos include layer flicker as they are directly ripped from an arcade copy through a overqualified recorder, rather than a recording of the computer screen itself.
This is the original Positive. The character is Sunny.
