If you're making a platformer, always, always, always make sure it feels good to move your character around.
There's a somewhat popular urban legend that at the start of Super Mario 64's development, Shigeru Miyamoto wanted to make sure that Mario felt fun to control just by himself. To accomplish this, he simply tested Mario's movement in an empty white room and polished it until it was perfect. And it shows!
If you're not sure about your physics and movement, make sure you get feedback. Even if you are sure, make sure you get feedback. Something that may have felt normal to you may feel weird to somebody else.
And remember: don't take all criticism equally. Oftentimes criticism is helpful, but keep in mind that not everyone shares your exact vision for your game. After all, if Miyamoto gave Mario a rocket launcher in Super Mario 64, the experience wouldn't feel as unified as the final product*. Learn to discern between these types of criticism.
*On the other hand, this sounds amazing. Take notes, Nintendo.