Grief Syndrome is a doujin game by Twilight Frontier which was released at Comiket 80 on August 13, 2011. It is a side-scrolling beat-em-up featuring the characters of Puella Magi Madoka Magica and up to 3 players can play locally (all gamepads/keyboards connected to the same computer). Twilight Frontier has also released a trailer that can be viewed after the jump. Those interested can get it from here. Be warned though as it’s a Japanese site. Thankfully, the game features English menus so you won’t need to know Japanese to enjoy it.