The Port Moresby-born winger had an injury-affected debut season with the Storm and rated his first year under Craig Bellamy as a "six or seven" out of 10.
Still boasting 16 tries in 17 NRL games this year, the 21-year-old will form part of a formidable Kumuls backline that includes South Sydney's Alex Johnston and Melbourne teammate Justin Olam.
PNG are in a group with Cook Islands, Wales and Tonga and enter the tournament full of confidence after knocking off Great Britain and Fiji in their two most-recent outings.
A fixture against the Tongans in St Helens next Wednesday (AEDT) looms as the biggest obstacle to the Kumuls finishing top.
"At the last World Cup we got to the quarter-finals and our goal is to go one step further and get into the semi-finals," Coates told AAP.
"All of the boys are really invested in the World Cup and we are in the running to finish in top spot.
"We're confident in ourselves and that if we get the little things right I feel like we can accomplish that."
The Kumuls are based in Warrington after undergoing a camp in Papua New Guinea.
Coates hadn't been back to birthplace since he was a seven-year-old and said he was taken aback at the rockstar's welcome afforded to Olam.
"To experience it firsthand and then see the reaction 'Juzzie' got when he walked out of the airport - everyone loved it - and there's pictures of him all over the billboards in Port Moresby," Coates said.
"It was pretty emotional for me too, because I don't remember too much from when I was a little kid running around."
Prior to his ankle injury Coates may well have been in the reckoning for Mal Meninga's squad but said the chance to add to his solitary Kumuls cap was a burning ambition.
"One day I do want to represent my dad's side but I felt like this World Cup was pretty important to play for PNG," he said.
"When I sing the (PNG) national anthem (it feels special). Growing up I always followed the Kumuls like crazy."
