A rather annoying bug I noticed is that when you click the simulation button, your mouse is place at the bottom right of the screen currently in use. The problem with this is 1. It can be confusing of where your mouse has just gone, and 2. If you have another screen, you can accidentally move your mouse one pixel to the right and suddenly the app is disabled (This mostly happens if you start a simulation and then immediately right click to move the camera around). This is quite annoying, and has even screwed up my tracks since some of your movements still carry over even though the app is minimized.

Also windowed fullscreen is always a nice feature that I adore in games.