I tried two times. I enjoyed playing it, it is a nice concept (doubt it if is something new, otherwise impressive!)
I didn't run into any bugs. The concept wasn't clear after doing the tutorial. I was simply pushing numbers through a long hallway.
I think the first level was better at explaining the concept. Perhaps the tutorial should be more like a very easy first level.
I didn't pay much attention to the end screen. But I'd consider weighing 'taken steps' as more important compared to 'time taken' in an end score.