If your having trouble finishing the level, I'll be posting tips once a week.
Tip 1. Defeating the Koloss with the sword.
I made this one intentionally hard to kill in other to force you to look for alternative ways to advance using pushes and pulls, and that's the easiest way to win this fight, while very powerful Koloss are also not smart, so if you get behind them you'll have a few seconds until they realize where you are. So by jumping and pushing from his sword you can easily get behind him and score melee hits.
I won't lie it's still pretty hard, took me a few tries to record that, but in the end you get his sword!