Because we are looking at a Third Person (Limited Omniscient) narrative, we really only know Rainsford’s thoughts. And only when Rainsford “escapes” near the end do we get a glimpse of Zaroff’s thoughts:
Two slight annoyances kept him from perfect enjoyment. One was the thought that it would be difficult to replace Ivan; the other was that his quarry had escaped him; of course, the American hadn't played the game—so thought the general, as he tasted his after-dinner liqueur (2.31).
Other than that, we’re with Rainsford.
“The Most Dangerous Game” is the story of Rainsford’s transformation of perspective. He begins by having no sympathy with animals—or prey—and ends up experiencing precisely what the prey does when being hunted. But Rainsford can be a little frustrating as a narrative voice. Even though he openly agrees that humans should be excused from the horrors of that experience (which Zaroff thinks is a “romantic idea about the value of human life”), he doesn't reflect upon his original view at end after all he has experienced. In fact, he ends up killing the predator and repeating the very actions he condemned earlier, which was killing humans.