The Queen of Heart 2001: Party's Breaker is a 2D fighting doujin game by Watanabe Seisakujo featuring the characters of Leaf's Comic Party.
Playing the game is relatively simple, one has the 4 directional buttons and 4 buttons for (special) attacks. On my system, which is Windows XP Professional SP3, the controls for player 1 are up = [up arrow], down = [down arrow], left = [left arrow], right = [right arrow], weak attack = [n], medium attack = [m], strong attack = [,], special = [.]. The controls for player 2 are up = [t], down = [g], left = [f], right = [h], weak attack = [z], medium attack = [x], strong attack = [c], special = [v].
If playing with keyboards only, it is advised to use two separate keyboards.
The linked website plus the included text files are sufficient for understanding the game, its characters and its mechanics.
The game version is 1.005 and has all characters unlocked that can be unlocked. Anyway, enjoy the game.