Kompany, who took over at Bayern this season, enjoyed a winning Champions League debut as coach with striker Harry Kane scoring four times in a game with the most goals by one team in the competition's history and the second-biggest winning margin.
"It is about three points," Kompany told a press conference. "Nine goals is a bit unusual but it was a lot of fun. The energy was good, the team showed the right spirit."
"We have played just one game and not more than that. It is now about the next game, to keep going."
It was not all praise from Kompany, who saw his team lead 3-0 at half-time but concede two goals in two minutes shortly after the restart as the Croats tried to find a way back.
"We scored nine but we conceded two goals. We conceded those goals because we were a step too late. Still, we stayed calmed and then had a good evening," said the Belgian.
Kane's four goals saw him set a record of 33 for an English player in the Champions League. The England captain also scored a hat-trick against Holstein Kiel in the Bundesliga on Saturday.
"He is motivated and for me as a coach, it is easier because if you have a top player who is himself so motivated it makes things so much easier," Kompany said.
"He is a leader, captain of the national team. Players like him, they know they have to rise at these moments and that is what he is doing."