I am having a good time in-game.
I am happily surprised how well the parkour controls work, it's close to Mirror's Edge feel of movement, yet not as elegant animated. But I guess that fits the game better anyway.
Zombie bashing is fun, had my first big boss Zombie and it actually takes some time and work to kill it which was good. It feels intense and the controls work well again. Overall it seems to be a really good Zombie game. At least from what I've played yet which isn't too much.
Only thing: technical issues but it is very well playable for me, maxed out settings at around 40fps (I don't need those 60... never really understood why tbh) but there is obvious room for patching and it doesn't feel like a lost cause (*cough* AC Unity *cough*).
Don't buy yet if you're not German, wait for some patching.
German players basically have to buy now. There are strong rumours that it will be on the index in a few days and Steam will add a activation lock for German IPs.
Bought my key at MMOGA and didn't need any VPN... worked/works like a charm.