All right, I'll be honest with you. It's bad and you overdid it.
Simply showing the clips w/o any music would have been better.
- Why did the music change from the first to the second clip? It's weird and physically hurts me.
- The heartbeat effect on the third/fourth clip was complety unnecessary since there wasn't happening anything scary / the plays weren't close at all. Literally the only reason for the heartbeat effect there was the music, this means that the gameplay didn't match the music / the music didn't match the gameplay.
I like though how you times poppies abilities / the kill on the vayne with the beat in the 4th clip. But the veigar kill was out of sync again.
These are just some examples. You can avoid this by simply showing the gameplay with some not so bass / beat heavy music in the background, where you can maybe still hear some of the ingame sounds. A proper montage is hard to make since it requires a lot of gameplay to be cut in a way that fits the music.
Here is an example of how the gameplay has to fit the music: https://www.youtube.com/watch?v=PeaM2bbmNFU
Notice how there's a spear finding it's target on every "BOOM HEADSHOT!" beat, but unlike your song this one also had "free for all" parts (the parts of the song w/o "BOOM HEADSHOT!") where you could fit all the plays in that don't fit in the beat heavy parts.
tl;dr: your gameplay doesn't match the song so it's bad.