So the game is  on steam atm with a 75% off, which is 5 euro. So my question is, is it worth  the 5 euro. 7 h till is back to normal price

I was seriously excited for the game before it came out, went and brought it on day of release, played it for a few days and then returned it, it was a real disappointment in comparison to what it was billed as (open-world, incredible graphics it was not.)
Having said that, recently I've questioned rebuying it for £5, which I may well do if I run out of games to play.
I'd say if you don't mind a few glitches here and there, and you know what style shooter you're getting yourself into, it's worth the money. Best thing to do is watch gameplay videos and see what you think.

downloaded the demo -> ran like shit on my PC -> i passed

Only buy it if you have 3 friends to do coop.
The AI is shit, but coop makes it decent fun. I wish I had had people to play coop with. As it is, it remains uncompleted for me.