Stage 3 environment for my platformer shooting game

The is my 3rd environment for my platformer game which took me roughly 5hrs to make

a scrapbook of my art references

this is a initial sketch for the scene to determine the layout

first stage which the base colour is made

then i add a initial layer to create a line for a opening

a deeper colour is added to show depth in the scene

the mock up of the jet is added in

then later i added to show wear and tear on the jet itself

the final details are added in to create a more unique scene