I don't have anything to add on the game itself, especially since it seems like the other commenters are more into this type of thing than me. However, I would recommend in general when using Unity that you post a downloadable version as an alternative to any web version. I had multiple issues that seem to be related to my computer just not being very good, and such issues are usually worse in a browser.
In case I'm wrong about the cause, the issues were as follows: 1. the game didn't seem to go beyond the instructions screen on the first try. On reloading though, it appears that it was just having trouble loading. I've noticed unity games sometimes take a huge time to load on one try and then no time at all on a second try, which worries me to no end for technical reasons. 2. the plants were refusing to grow at all, even after minutes of watering. The issue went away after pausing and scrolling around the page, though, so I think the game just was having trouble loading the models.
If no one else complains about these issues and you can't think of any reason for them, I wouldn't worry about them.