Villain was weak tight and got chipped away more or less.
Flop-donk looked very weak to me, so I raised it up.
Perhaps 220 is a bit better? I put him on a draw or some kind of king, cause he had played 100% fit or fold in that match. The draw seemed more likely to me given his bet size.
On the turn I got a bit unsecure what to do now. I thought about making a big raise, but this would have led to a huge pot on the turn with little left in his stack for the river. Also I did't really love my hand with the weak kicker.
So I only called with the plan of playing the river like I did when a non heart card hits.
Can it be played different? Better? Villain was weak tight.

How do you mean weaktight? Folding a lot pre? c/f a lot postflop or c/c a lot?
flopdonk looks weak, i agree, so raising seems fine although id make it a little bigger. If you perceive his turnrange as being similar to floprange id just raise turn too, maybe not too huge but enough to jam river.
This might be completely wrong if you literally mean this was like the first time he showed any aggr since a while, id not really like my hand otr in that case

With weak-tight I mean he had only 27 pfr - he called only 35 % oop and I only minraised. He played fit or fold, if he was in a hand and he folded nearly 100% to a 1/2pot c-bet on the flop.
And this was literally the first hand he really played and he donked away.
So I was alert and wanted to be cautious with the K8o.
After giving it some thought though I think the turn call 60 into 600 is a BIG mistake and can perhaps only be justified in regard to the extreme tight passive weak gameflow.
I just didn't feel good stacking off with K8o in that spot, so I didn't want the pot to grow on the turn. Odwise a no go for opponent possibly holding a draw.

I actually dont mind the check raise that much since he probably doesnt have a whole lot of air in his donk range based on your description and kx is discounted cuz u have one. I think size is fine also. However turn is a mistake pretty clear block bet from a weak player so you should raise it again and take away his odds to draw. river is good call imo after that turn bet. Rematch him tells for dayyyzz!