Character Concepts.
The original concept for Isaac was this monkey, he is a bit darker then the final concept but here is one obvious difference, this version is facing forward. This made it difficult for me to make animations and o make those animations work. I now know how to make this concept work but that is for another project.
This is the jumping sprite for the original concept, it is very basic but it does its job as it looks like he has just jumped of the ground/ off a wall.

This is the final version of Isaac, this was lass time consuming to animate so it was quite easy to apply the animations to the game, compared to the previous version there are half as many animations used in the game. and the sprite was easier to make.