While I have not played Guandan specifically, it is a climbing game, like Big Two or Tichu, which I have. The main difference seems to be scoring by the card rank level and the wild cards.
BGG entry: https://boardgamegeek.com/boardgame/273913/guan-dan
If the leg press was good for you, then squats seem like a good option. Here's a good place to start with lots of options for progression from whatever level you are starting from.
Every accusation a confession.
Azul is better with 2-3 players than at 4.
Others that play well with 2 & 3 players: Dominion Race for the Galaxy Castles of Burgundy
Moana.