Hello! I'm completely stuck on Level 21 and would really appreciate any tips or hints you might have.

First of all, thank you playing the game. Level 21 is the last level, and it's especially difficult. I suppose you could check the VOD from TigerJ and hit pause when you want to try something new by yourself. Here is the link with the timestamp : https://www.twitch.tv/videos/430916665?t=01h15m53s