User summary
ギルティブロッサム (Guilty Blossom) is an Uno-like card game, but this is a co-operative game. All players win if any one player gets rid of all cards in their hand. All players lose if the apocalypse number reaches 13, or players take total of four damage.
You may play a card if that card matches its color or number to the top-most card of the discard pile, or draw a card if you cannot or don't want to play. The apocalypse number fluctuates according to the cards played, so sometimes you have to draw a card even when you have an eligible card. But you cannot draw too much, because you take damage if you have more cards than your hand limit. All of you should discuss who will be an attacker who gets rid of cards, and who will be a healer who draws cards and keeps away from apocalypse.
Publisher's summary
協力型のウノです。誰か１人でも手札を出しきれば全員の勝利となります。手札の出し方のルールはウノと同じで、直前に出したカードと色か数字が同じなら出せます。しかしカードを出すたびにダメージが溜まっていきます。時にはダメージを回復すべく、あえてカードを引く必要もあるでしょう。誰をアタッカー（手札を出し切る役）にし、誰をヒーラー（限界まで手札を溜めてダメージを回復させる役）にするのか相談しながらゲームを進めましょう。