Yep!
It's Mach 5 from Speed Racer.
Rodrigo Pascoal, the art director, is a huge fan of that anime.
There are 2 more easter eggs, but it's too specific, because only people who knows the first 3 guys in credits should understand the easter eggs.
Years ago, like 2008 or 2009 to 2012, I think, they had a website called OrionGames (you still can find the account on X/Twitter), where they made a, small but great, game podcast with some friends called Orioncast and the Orion logo is something like the input/output symbol. You can see the references to Orion logo in the doors of start area and in the bottom left corner of the inventory where almost says "Orion".
Great guide dude, thanks for the help.

I will update it today with the other parts!

how to get the last power core (red)and the document before the last room in Serendipity Moutains (lasalle where we see SV-1 units in hibernation)?

I saw the hat guy and it really gave me a feel of a marketplace but I had no idea about its origins.

Its ok. The producers mix many easter egg from brazilian people' childhood memories. There some easter egg just brazilian people will understand, for example: in atomic city aside Mrs Florinda Restaurant, there is a market with a hat little guy outdoor. This easter egg is inspired in famous brazilian marketplace called "Casas Bahia".

You could be right! Btw I completely forgot about this guide. I should finish it! But I also remember I searched for references for a Batmobile and somewhere saw a model that looked like this. Besides when I saw the car for the 1st time I immetiately thought about Batman.

Its not Batmobile. Its Mach 5 from Speed Racer.