statistically, the ninja boss in level 14 has 2500 health. Fully upgrading everything meteor related only gives a total of 2000 points worth of meteor damage, so you have to do 500 points of damage with your one hit and other things like burn of freeze, which is purely chance and therefore unfair.
I honestly did not like this game compared to the other two, the checkpoints are way to far back, the bombs were a bad idea, it was unbarraby unlinear, metroid was more linear than this, and most of the upgrades you bust your ass for are just things like sheild or bullet deflection, which in almost no way helps you advance to new places.
3/5, if you took out the mario and added a original character it could have been rated higher. It doesnt even have to be that original, it could have been an different colored mario and you would've replaced the copying feeling with a nostalgic feeling.