I've been using this a lot! It really is helpful for keeping track of when to work and take a break; I was using webpage timers before, but for some reason they never seemed to want to go off reliably and the tab tended to get buried with the rest.
It's a bit unusual for a game of this size, but might I recommend a bit of DLC? Once you unlock everything, there's nothing incremental you can spend your peas on. I'd be more than willing to pay a few more dollars to add in, say, ways to buy outfits for all your cute pixel friends, or decorations for the farm. (I actually delayed clearing out my entire field because I liked how some of the "obstacles" looked.)