I like the twist on a temple run game with a bullet hell. Everything looks nice visually and the music and sounds are nice. My feedback is the attack needs a bigger hitbox as the timing is really tight and I had a few deaths trying to figure out when I should actually attack. The hourglasses felt more like a detriment except for the yellow one since the slow down slowed everything, including your jump and attack, and the speed up did the same, so the timing of everything got thrown off. The bullet hell section made sense with the slow down hourglass, but the perspective change was a bit too fast and too close to the characters because you're still moving forward and the hour glasses fly by with barely enough time to react. I would like to play more of this concept with a bit of refinement because an autorunner/bullet hell sounds like a great combo.
Also side note: the math you're using for calculating the milliseconds has an edge case where it'll be 1000 instead of 0-999. You might be using the same formula I found before as I had the same issue in my game as well. You just need to check for this case to stop the timer from jittering every second due to having more digits than the UI is expecting.