This game has a neat concept, with some really nice visuals from everyone involved, and I have to give you guys props there, but this game has a pretty big issue when it comes to balance. Ranked from easiest to the hardest to fix, the player always going first gives them an unfair advantage, the power-ups are too powerful, and the cpu's are too incompetent for their own good. I did a lot of games using as many powers I wanted to (one for each character/21, I did it as a challenge because I thought it would be harder), did a few using one per round max (5), and did a couple using none at all (3), and every single time the player wins because they are just given too much of an advantage.
Firstly, by giving the player first pick, it always gives them better or equal odds at getting whatever effect they choose to look for (even without the use of power-ups) because you are either always choosing from a 50/50 scenario where it doesn't matter who you give it to, or are able to decide what to do based on which potion colour was in the majority, giving it to the cpu if red, or to yourself if blue. By giving the player a constant advantage over the cpu, it almost always cause the player to be one or more sizes smaller than the cpu at all times because it removes a lot of the luck that a roulette game should have. A good way to fix this issue would be to make whoever is currently losing go first, with ties being random (yes that even includes the start) since now the person falling behind gets a slight leg up on the other player.
Secondly, out of all of the games I have played, the ones that I had the most fun doing were the 8 games where I limited myself in terms of the potions, because it actually felt like I had some chance of losing if I got too unlucky. Simply put, the power-ups are really powerful, and while that isn't inherently a bad thing, because of how much the player is allowed to use them (and how infrequently the cpu does in response but I'll get to that later) it basically guarantees a win which sucks the fun out of trying because a lot of guessing as to whether or not you made the right choice is taken away. In those 21 games where I could go as crazy as I wanted, there were times when I completely skunked my opponent because I was able to use multiple lethargies and give them 2-3 reds in one turn. Alongside being able to use so many, the amount of things that you are given every turn means that you will very rarely run out of options meaning that there's no downside for going crazy with what you have, you are given 2-4 every round, and because of this it was how I was able to get the three lethargies needed to do what I described a couple sentences ago. To fix this issue, the best things to do would probably be to limit the potions a player can use per round to one, while keeping the refill amounts the same, OR allow the player to use as many as they want at once, but only give them four at the start to add more thinking into when to use their powers (I would heavily recommend not doing both because then it would basically defeat the point of potions in the first place).
And lastly, the cpu's are too incompetent to be a threat, in every type of game I played there were multiple instances where the cpu would give themselves a potion guaranteed to be red (one time even in a two potion round where the red one was the only one left), they also very rarely use the powers that they have at their disposal, almost never using multiple unless they're getting rid of stuff to make space for different powers, using the looking potions and still putting a red one on themselves (yes this did actually happen once), and even using two switcheroos on the same potion (yes, this has actually happened once as well). Even though it is definitely an issue, I would not worry as much about this one, programming in itself is already really difficult. and I can't even image how difficult a well balanced cpu would be to make, however, because cpu stupidity is not the only problem, the balancing issues compound, seeing them accidentally shoot themselves in the foot isn't as funny to see as it would be normally because it happens a noticable amount. I don't know much about programming a cpu, so I can't give much of an idea in this regard, but maybe you could try to add a list of previous actions for them to go off of or something, because it feels like they don't have a short term memory, not knowing what state the potions on the table are in.
I like the game, and I think it has potential, but right now, because of how easy it is for the player to win it feels less like a roulette game where you're trying to test your luck and your critical thinking, and more like you're just bullying the computer players. I'm sorry if this essay comment came off as harsh, but if the game is to be as good as it could be, it does need quite a bit of work with balancing. I'll stick around to see where you take this game in the future.