I mean, every endless runner game is repetitive in my mind, but this game has 7 different areas so the scenery and obstacles vary quite well during infinite mode.
I never found it boring, since it is pretty fast paced and you are constantly moving/making decisions, but then again, most of the times I played I streamed it so I had an audience to talk with while playing.
It's also not without it's faults mind you, as there is some occasional freezing and cheap deaths, including the final boss fight which is just downright stupid. I think the game itself makes up for any shortcomings though.
My $0.02, but obviously, experiences can vary
.