oooo what a cool concept and expansion of an idea!
To start with it obviously hits the theme 😅but I like that you used it in terms of a game that already exists, so it doesn't feel like it was shoe horned in, and then subverted the expected rules. and i gotta say it definitely improves connect 4!
visually its very interesting. I like how the actual game elements are kept simple but then the Balatro style background is mesmerising (its also a nice touch that majority colour in the bg changes each turn). I think it was a really good choice because it keeps the game immediately readable and understandable but then you can see the polish you added on top with the wavy rainbow 'choose a modifier' and the effects when you play modifiers.
It was a pleasant surprise to see an AI opponent option for a game jam, and it did a pretty good job against me most the time.
Its a shame there is no sound because given how well the other polish is added i think it would have provided even more impact, but I think you did good to focus on nailing the bits you did present rather than losing some of it by spreading yourself thin.
really cool concept that feels like it explored something different, good job and nice entry. thankyou!