Welcome in this very small world !

You can turn off the music by pressing "Escape" and shutting down the volume

Really atmospheric! Both graphics and audio were great, the music especially put me in a farming mood... My one criticism is that there was never really any reason to have more than one plant going at a time. Given that plants grow by manually adding water, which can seemingly only be done to one plant at a time, the best way to quickly get seeds I could see was to get one plant at a time, water it, then start on another one.

One suggestion might be to remove the need to water plants and have them grow automatically over time instead. Then, make the acid cloud faster. This way the player has to protect their plantation properly while they wait for the plants to grow. This also makes having many plants the most efficient way to play the game, so it becomes more natural for players to build a large farm and then start stressing out about having to protect all of it.

Other than that, really great job!

One minor thing - was this made for an AZERTY keyboard? You said that 'Z' was the action key, but on my QWERTY the action key turned out to be 'W'.