I really liked the main gameplay loop of managing both the plant creation and the oncoming waves. It was fun to experiment and see how different fertilizer mixes affected the plants.
I wish the mixing elements had been communicated a little stronger in the game. I feel like a few UI tweaks could have really helped me as the player understand what different features were doing. Some examples that come to mind are being able to drag the plants and see where they would be placed before they went down, an indicator for what different fertilizer mixes created which plants (maybe a silhouette of which plant was mostly like based on the mix?), and a UI element helping connect the changes in fertilizer amounts to changes in damage output/speed/etc.
Overall, really enjoyed the game's theme and I had fun blasting through some waves of evil slimes. Thanks for making it!