Haha, I had no idea QWERTZ did exist :D
The checks are indeed never explained, but I tried to add a medal system. Although I did not implement it in the way that I actually wanted. It was an experiment that I can retry in a next project :)
The 1 means that you were as fast or faster than me. Mostly, the 2 means you were slower than me, but not that much (it was faster than 3/2 of my time). And a check means you were faster than double my time.