Really smooth gameplay and great soundtrack! I think I went on a few extra runs just to listen to the OST a bit more haha. There is also good variety in the obstacle waves.
The upgrades are really useful, but they make the game a bit too easy as I feel like I could keep going forever with the shield upgrade. Maybe the difficulty could gradually increase or the health pickups could be less abundant (or buy them in each round instead of making them permanent). The speed increases after a while, but when you bump into something, you slow down again, so you can safely recover the lost health in no time.
Overall, the game feels really fun in the beginning, but you reach fatigue eventually as things become too easy. If there were more challenges, this could become quite addictive. I can especially see it as an infinite runner kind of mobile game. Cheers!