This is a Strands, a type of puzzle most associated with the daily NYT strands.
The objective is to form words using paths through the letters, and eventually to use each letter once. There is one Spangram that touches opposite sides of the grid, and usually describes the round theme.
Theme: Words or phrases starting with the word "RED" or "GREEN", but as they would be displayed in Only Connect's Missing Vowels round.
Spangram: MSSNGVWLS (Missing Vowels)
Words: