I have got this impossible since now 2 years and I can tell you that is was extremely hard to get...I have got many impossibles and this one was the hardest. Gl everyone who is trying to get it!
I managed to get hard badge long time ago. Here's how i passed the last mission on alien: Kill everyone whit any weps.After that you’ll have the raze soldier left.Try using changing ur weps rapidely, that means use the ion cannon,switch to shredder then finish it whit a holy grail but BE SURE TO ALLWAYS HAVE 2x AND ARMOR!
For everyone saying that impossible is impossible: The impossible badge is not really hard, and not really easy. Because you need ALOT of practice to get it. (And i mean by ALOT really ALOT :)...)
IF you think the game is "easy", play it on hard difficulty.(You unlock it by completing the game on medium difficulty witch you unlock by completing the game on easy difficulty...)
The secret archivelemnt (the ? Last tier) is called "Sea of Lava", i posted a picture of it on the forums if anyone wants to see (SCGMD4 Discussion thread)
Even if that was 2months ago...
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