Found it very enjoyable until I ran out of upgrades, it felt challenging enough where I'd be excited to finally get an upgrade. Minigames felt very impactful at the start, where you increase your potential to get a good upgrade, but later in the run doesn't feel like they matter that much.
Personally I found the theme fit very well from a vibes / aesthetics perspective. The hero gives off Rocky-esque vibes, i.e. growing stronger, especially the poses after minigames, so I wouldn't write this game off as not fitting the theme at all!
Also bonus style points for sound effects, absolute gold :p