This is an addicting game and I love how they continue to release new levels. This is especially good if you have an Apple pencil, so you can be more accurate. I have passed all levels of three stars and can not wait for more to come out! (Just finished the 40 other levels published a few days ago).
A few notes. Yes, there are a lot of ads, but it's only a few dollars to get rid of them. I chose to just cope with them. Ratings that say you're forced to see an ad to get three stars is wrong ̵
Also, a few do not seem to get the stars … it's not based on how much water you have saved. You only need to save enough water to make the glass happy and it does not matter how long. The stars are based on how much "ink" you have used – the less the better. You will see the line go down as you draw, if you cross the first line, you are down to two stars. You want to see the stars next to the line decrease to two when it happens.