Well, I tried the demo too. It wasn't that bad. The game feels good to play. I notice some difference on the graphics, animations and gameplay, but it's nothing from other world like they pretend to make us believe. The biggest change I've noticed were on the goalkeepers. The gameplay is a bit slower. I kinda like it.
The presentation, however, I have to agree with you. I had to reduce contrast/bright so that blue color didn't hurt my eyes.
In general, it's an update of PES 2017, with some good new stuff, but also disappointing that they could do more with the game and they won't. Konami should lower the price because we aren't paying for a completely new game.
I really hope Konami starts putting more effort into PES, it has the potential to become the greatest sports game ever but the developers need to bring new features, game modes and, specially, new leagues (even if they are fake, or like Portuguese league where we have 3 big teams licensed and then the rest is fake, option files can always fix them).
They need to stop focusing on Barça and look to the football in general. They also need to add more stadiums and improve the atmosphere with chants, at least for the licensed teams and not only for those premium partners. (I love playing on Signal Iduna Park or Anfield, the atmosphere and the chants are terrific, I wish they did that for more teams). And, specially, they need to listen to the fans. If we don't buy the game, they won't get money. Maybe if we all stopped buying the game year after year (I usually don't do that, I give a break of 2-3 years unless there's something really good) they would realize that we want new stuff.
I love PES because I can create all the teams I want and I never see in games, That's why I don't care about licenses. I wouldn't buy the game if we didn't have fake teams to edit.
In conclusion, I like the gameplay, the graphics and the new animations (even though it hasn't changed that much as they say) but I will only buy the game if we have good tools for editing and if they keep or improve the amount of fake teams we had in PES 2017 so we can create our football world.