The game crashes if I use x64

Make sure you run Bin64/Crysis.exe, not Bin64/Crysis64.exe. Opening the task manager while in-game should show that Crysis64 is running.

Curious, what is a 64bit .exe. There's a few games that have them I think Witcher 3 also has a 64Bit launcher. Does it use more CPU or something?

Ah, got it. :)

Addressing area is larger so the processor can work on more at the same time (if it can handle the load) and the amount of memory that can be used is much higher. The latter has the largest impact in almost all cases.

I suspected as much. Usually it's high games and mods or apps that use a 64bit exe

I suspected as much. Usually it's high games and mods or apps that use a 64bit exe

Doe the CrysisLauncher.exe file use the 32-bit version of Crysis or the 64-bit version?

That's actually really cool imo.

GoG has living people to interact with in order to upload a game. They tend to ask pesky questions like "Is there a 64-bit version?"

Steam... just doesn't ask anything.

Which still is odd because the game launched in 2007 with a 64bit version.
I'm quite surprised Steam didn't include it because it was already there.

This is why I love GOG. They even made a custom launcher that detects the bit version of your system! :D

AFAIK a 32 bit application can only use up to 2 GB of memory.

For the game this doesn't matter that much, but for the sandbox editor it can become an issue :)