Nice interpretation of the theme! I like the idea of having a “testing lab” to figure out the side effects of the different potions, and making the player spend money if they want to really figure out every possible side effect. It took me several tries to figure out how to beat the first boss, when I was rushing into battle without investigating side effects well enough.
The sound effects and art are nice - I especially like the potion sprites. Some additional visual feedback might be nice to show different status effects like poison, burn etc. Perhaps having numbers on the HP bar would also make it easier to tell how significantly the potions were impacting attacks / draining health as well.