Sadly i couldn't watch any of the games, so the following opinion will only be based on highlights:
France vs. Uruguay: Expected winner, although both goals were rather out of nowhere. Apparently Mbappe learned the wrong things from Neymar, but unlike him he has still enough time to grow-up.
Belgium vs. Brazil: Surprising winner, apparently the absence of Casemiro hurt Brazil more than most people thought. I am happy that Clownmar is out, but on the other hand Brazil clearly got screwed by not getting a penalty when Kompany fouled Jesus. Absolutely shocking "mistake" by the referee/VAR.
England vs. Sweden: Another goal after a set piece for England, nothing new. Sweden didn't look as aggressive in defense as in previous games, maybe they were tired or the absence of Lustig hurt them.
Croatia vs. Russia: After the group stage noone would have thought that Croatia would need 2 penalty shootouts to beat Russia and Denmark, but those games showed that they clearly have a problem with breaking down defensive teams. On the one hand i am sad that the host is out, on the other hand i am happy that Russia is out. Their first penalty was absolutely shocking, possibly the worst penalty since Zaza's penalty against Germany.
Surprisingly overall the matches were less close than in the previous round. In the round of last 16 only one game was won by more than 1 goal, in the quarterfinal 2 games were won by more than 1 goal. Still no team played brilliantly at this world cup so far, most goals are scored by coincidence, after set-pieces or after goalkeeper mistakes. Most games are very close but not on a very high level in my opinion.
Predictions:
France vs. Belgium is at least 60/40 for France in my opinion. The french defense is just much better and they have better alternatives on the bench. For me they are still the clear favorite to win this tournament and this game might very well be something like an early final (although the same has been said at 2016 european championships and then Portugal won the title).
Croatia vs. England: I think England is the favorite in this match (croatian players will surely be exhausted), although i hope that England won't make it, but i don't really see Croatia beating them. I never would have thought that one of those teams would make the final, but both had an incredibly easy draw (although probably not as easy as the draw for Germany in 2002). I think it would only be "fair" if either France or Belgium would win the title, they just had a much more difficult path to the final. As long as neither England nor Croatia win their first world cup here i will be fine. Personally i would prefer to see Belgium winning it, since France just has too many annoying players and the french team is bound to get even better in the next couple of years, so they will get enough chances in the future to win some big titles, while a chance like that might not present itself again for Belgium.