The items you picked up (Sunny Flower, Toxic Mushroom, Red Rock) are actually craftable modifiers. If you press P and drag them onto your arrow (left inventory slot), they apply special effects to your attacks. -> After equipping a modifier, press C to switch between different dart types.
AHHHHHHHHH it makes sense now! Okay! It’s true that I forgot to try switching between dart types, but it’s mentioned in the menu. Thanks for clarifying <3 Hope you can make the webGL build so more people get to check it out <3