Yeah, ideally I should've made the font changing not so random. Now it just selects out of 2 available sprite frames every 3 (as far as I remember) seconds so, because there're only 2 frames, sometimes (and in this case it happens pretty often) it selects the same one, so it's kinda hard to spot the changing tempo because of that. At first, I had 3 frames (there also was italic font style), but it seemed a bit too much, so I reduced it to 2. While it was 3, it was a bit easier to spot the changing tempo. But still, thanks for the feedback! Every bit of it is some knowledge for the future)