Hello, I recently bought Jazz Jackrabbit 1.

AFAIK it's the US version. I'm still waiting for the game. Meanwhile I've looked whats inside the box. I should get this disk.
Then I've noticed there's a EU version of JJR1. I'm confused because it should have four disks: EU disk

So my questions are:
1. Does the US versions contain only one disk and the EU four? If yes what are the differences of the games?

2. At least does the US version contain all six episodes?

3. What is the origin release/version? The US one? Or were both versions released same time?
To be honest the EU thing looks a bit like a budget version...