Solitaire Zero21 is a solitaire variant where one gathers number cards to maintain the sum between 0 and 21 throughout 75 levels. This is a delicate game of planning and strategy that allows special cards like MIN, MID, and MAX to adjust your sum. Relaxation and mental stimulation have a fair share in this game to engage and satisfy each player. Whether one relaxes or sharpens their mind, Solitaire Zero21 grants delightful gameplay.