bad flow,
no detail, nothing artistical also the layout is bad. (recangle-ish)
3 important things for the next map:
1 dont make spots where you can get stuck
2 no dead ends
3 avoid too long corridors or too open areas
you made the first mistake very often in your map (many spots that are not accessable easy)
the players are supposed to jump around there and move easily and fast.
look at complex.. every single platform is accessable easily and you can jump from platform to platform..
try to begin with the layout first too.
Flow1
Flow2