John Aloisi's men have struggled for consistency this season, sitting ninth, but are just two points adrift of sixth-placed Brisbane Roar.
Tadic, 25, has netted four times this campaign after a slow start and said the evenness of the A-League made it different to competitions across Europe.
"It's good (the level). It's difficult - a lot of running. It's not easy to play and every weekend you have a hard game," Tadic said on Friday.
"It's not like some places in Europe where you have five good teams and then every two weeks you play against a small team and you can say it's an easy game.
"Every weekend here it's a hard game.
"We have still a lot of chance to get in the finals. There is not such a big difference in points so if you get good results. We can make it."
Temperatures in Melbourne soared above 40 degrees on Friday, and are expected to reach a high of 28 on Sunday when the Heart face the Brisbane Roar at AAMI Park.
Tadic said he needed time to adapt to the hot conditions, having become used to playing in the European winter.
"It's hot a lot. It's hot more than in Europe, so I need to get used to it," Tadic said.
"We feel good. We had a day off yesterday so we pulled up good and today we had an easy session. We're preparing and we'll be fresh for the game.
"It's the first time that I've come here and it's hot like this."
Tadic was full of praise for team-mate Golgol Mebrahtu, who has netted three goals in five matches in his first season with the Heart.
"It is easy to play when you have good players near to you," he said.
"Golgol is a great player and is still young and has a lot of time (to improve further)."