The young full back helped guide Wales to the final in France where only a second half fightback from England stopped Danny Wilson's men taking home the trophy.
The 23-15 defeat in Vannes was a disappointment but after a tournament where Williams' teammates became the first Welsh side to reach an IRB world final in the 15-man game, he reckons the side can look back on the tournament with pride.
"I want to try and play as much rugby as I can, this was my last season of Under 20's rugby so it was great to finish the way it has," said Williams, who can also play at fly half.
"It was nice to put in some good performances and hopefully I'll have a couple of weeks off and refresh before I'm back in with the Scarlets to start preseason there."
Williams missed the opening game of the tournament against Samoa but was at his attacking best in the clash with Argentina and the thrilling semi-final win over South Africa.
It was his jinking break, which helped set up Ashley Evans' late score against the Junior Springboks, leaving IRB Junior Player of the Year Sam Davies to convert and send Wales through to the final.
"It was a very positive tournament from a group and team perspective," said Williams.
"It was very disappointing to lose the way we did in the final but the boys can look back and take it on the chin. We had a good tournament and made a bit of history by reaching the final.
"We're very pleased to be the first Welsh team to make a World Championship final but it was a shame to lose when being 15-3 up and not quite finishing the job off."
Williams will now take some time off before pre-season and hopes to feature as much as possible for Simon Easterby's Scarlets.
He impressed for Llanelli in the Principality Premiership at the end of last season but after seeing Wales fall short in the final, Williams made no excuses.
"Up front England were very physical and I think they overpowered us there," he said.
"You could see they were a big bunch of boys and they finished off the game well.
"It's been a long three weeks and we recovered and rested well after every game and everyone has played the same amount of games so you can't make excuses."