Lovely game. I loved the dandelion and the concept of spreading the dandelion. My dad really hated them, and loves his grass lawn, but I think they rock. I think it's cool you implemented a fps warning to the user, and how smart it is in action. I think you should probably despawn dandelions outside of the plots after 5 minutes if it's not in the view frustrum to help alleviate the lag.
I think you did a good job of keeping players curious and wondering, because I did have multiple moments where I thought "oh this must be over, there must be no more content" but ended up finding more around some corner. I did give up after only one tablet though, because I was a bit fatigued.
With a game like this, everything has to feel nice because there isn't a sticky mechanic or challenge that drives the player (walking simulator sort of thing) and I think you've achieved that here. It was fun jumping around and goofing around with the dandelions.
I can't think of any really solid feedback, this is just really polished and good. Maybe I'd say there could be some design choices to drive more player motivation. Maybe if I knew about the tablet earlier, I would be content to keep looking for it. Since my world was lagging, that of course affected my player momentum.
Great job!