Thanks for playing! yea, level 3 was a tough one. You have to press the keys in order one at a time (one of the screenshot gits shows an example of optimal timing). Some people reported that their keyboards won't allow them to control the mom and play the dad at the same time, so they actually had to stand still with the mom to do the dad part (not ideal). You can also use a twin-stick controller and that should work too.
And yea, the idea was that sliding "down" the hill to the fishing hole is faster than climbing back "up" so walking up was intentionally slower. Thanks again for playing!