Ok, as you kindly sent the source code along the package that I recived, and is making this game free, and because my hobby is having ideas and sometimes proofreading texts...
I've took the liberty to examine scripts, do a minor spellcheck and bug tracking.
You're naive or naïve? Please use 'naive', as it is more widely compatible...
On script.rpy:6285 (Beta 4.1) Why does icari talks this line? Wasn't it supposed to be chigara?
' ica "That's why I like machines. You can fix them back up even after they break."'
Oh, and... Why if I cancel the warp (On mission 7) and solve to help Agamenon on last minute, I retain all aff that I gained with Icari and Ava, and gain more with Asaga?! Shouldn't I at least lose aff with Icari for deceiving her on last moment??
On Cera, after planet conqueral, it's write 'travel to and fro Cera'... Shouldn't this be 'travel to and from Cera'...?
And why the text saying that Cera was conquered by PACT is not displayed on Versta?
And why is this text an image?? You can use renpy to write text on it. Much more soft-code, much lighter. The same doesn't applies for CPU and memory, but will make changing text, adding or removing information as story advances etc. much easier.
But, err, this is mostly the 'Open Source way of doing it'. You can ignore it as long that you be able to fix aboves bugs.
If you chose to keep the images, but don't know how to allow Versta be updated, you can set a variable (eg. $Versta_Oucuppied="not") and use '$renpy.show('versta ' + str(Versta_Oucuppied) + '_ocuppied')'. So, while 'Verta_Oucuppied' is "not", it will show 'versta not_ocuppied'. str() is only for extra protection, so no one breaks the head changing the var to, by example, a boolean.
There is a function as well to you don't store cache. Will really make imagemap changes way easier.
There is also a code block to you allow the player update the game when a new release comes out... It could be really useful on a game like yours that keeps posting new updates.
You can also use "$ raise ScriptError('Cannot find the whale bonus preview!')" instead of 'show crash', on script.rpy:13273. This will lighten you package by aproximately 306 KiB. (Yes, I had problems downloading it. And that because my internet is fast. Nevertheless, after a close supervision and many trials I got it on my Linux machine.
Ehh... I'll continue this review later on.
NOTE: I've already found 4 reasons why change the bullet speed on graveyard scene.