I really liked the music and sound effects for this one. The handling of the beyblade felt nice and once you get better parts you can start to do some fancy moves. I also like how you reated the modular sprite for the beyblade, very nice seeing the parts change color. I was planning on making some upgrades to my beyblade game after the jam and this is great inspiration!
I would have liked some more decisionmaking on the upgrades. I just took whatever had the highest rarity and beat the game in one go. But at the end of the day this is a one week project, what you did is already awesome. Another quick thing would be to understand better damage numbers, who is taking what damage and how much life does your enemy have. I had some trouble with that on my game I need to figure out how to do so I've been thinking about it. Still, being able to track the enemy health is very fun for 1v1 duels!
It's interesting to see a beyblade game with this level of polish go on a direction so different than mine. Definetly saving this one as reference for upgrading my beyblade game!