It's Babble Royale pandemonium! Use the single shaded squares to fill up your tiles at the bottom, and then dispose of your enemies in one savage blow! (Hopefully this puzzle is still solvable/enjoyable even if you're not hip to this one niche Steam game.) If you like the puzzle, I stream very occasionally on Twitch (@henry_crosswords). Hope you enjoy!
Babble Royale explainer/spoiler: In the game Babble Royale, players create individual crosswords and "kill" other players by forming new words with their letters. Due to similarities, the game is sometimes jokingly referred to as "Scrabble Royale."