I found this game to be surprisingly challenging and interesting. However, whenever you accidentally place a peg on top of another or outside the area, you get a jarring ping sound. This can be turned off in the settings, but it really should be changed to something softer. Also, if a peg is moved on top of another, they should swap places. As it is, the pegs have to be moved out of the way, and it really makes levels much more frustrating, especially with the ping sound. These should be quite simple to fix, so I hope the next update comes soon.