Gachimon
One free spin every 3 minutes. Monsters are not fair. Neither is life.
Gachimon is a monster gacha you play in your browser. A new account holds one spin and nothing else. The next spin comes 3 minutes later, and spins do not bank. If you wander off for a week, you still get one.
There are 36 families across 5 tiers, from Common at 60% down to Legendary at 1%. Each family has 3 stages, and you reach them by spending copies: 3 for stage 2, then 4 more for stage 3. A lucky pull and a patient player can meet in the middle, and every spare copy is a choice between a third body on your team now and a stronger monster later.
Arrange your three, then fight teams near your rating. Fights have no input. All six monsters fire their moves on their own cooldowns, and where you place them decides what they hit. A typical fight lasts 6 to 9 seconds. Monsters are deliberately unfair, so get lucky or spend the time.