You could easily incorporate some of the jokers from Balatro. Just use a coin flip (or a shuffled Ace-Deuce stack) to represent binary numbers. Then just index whatever jokers from Balatro work with a standard deck and do a random lookup when you buy one with tokens.
You'd of course need to adjust the difficulty scale, but I think that's a good bit more variety than plain Solatro.
I love solo card game variations like this.
See also, Scoundrel by Zach Gage. http://www.stfj.net/art/2011/Scoundrel.pdf