Super Mario Bros custom tileset

[Novally]

Don't take this the wrong way, but your sprites aren't showing much improvement to be honest.

Here's a exercise to consider. Take one sprite or create one whole new sprite. ONE. Show it to us and we will offer you tips on how to improve it until it is satisfactory. Once you do this, you can rinse and repeat the tips on future works. It's not really a good habit to move onto a whole other sprite if it isn't in satisfactory condition.