You have a License which is great, but you'll also need a README file (these are two main criteria for open source category). You can fill out the README with what's on your submission page: https://iqpro.itch.io/balance-of-elements.
Physics is good, sometimes the items get randomly thrown from the scales. Small bug that when I click on something it won't unclick (ie. the object is stuck to the mouse). Sound effects are funky and fun, add some music too for more immersion. Great concept, and most of the items are fairly easy to figure out what they are and what they'd weigh. Nice work and good job fitting the theme.