Bookworm is a connect- or link-style word-puzzle game with levels and sliding-tile play. A bookworm named Lex eats words and needs the player's help with creating new food made of three or more letters via tiles distributed across seven columns. The player links the letters using green arrows and receives points as payment for their assistance. While feeding Lex, they receive more points for long words than short ones.
The player reviews the letters on the columns and randomly creates any word they can find using three or more adjacent tiles. Although the game provides the player with a Submit button that they can use after creating a word, Lex automatically chomps the words most of the time as soon as the player stops interacting with the tiles. The empty spaces fill with new letters. After Level 2, the player receives bonus word goals that provide them with extra points. If they repeatedly create bonus words, they receive higher bonuses.
Bookworm features red burning tiles that can destroy the entire play area with fire if the player fails to use the tiles before the pieces reach the bottom of the columns. It also features special tiles that take longer to burn and provide even more opportunities to create words and earn points. For example, green tiles that randomly appear increase the score. The player creates gold tiles when they form some five-letter words. They achieve the highest score based on the level, the number of used reward tiles, the scarcity of certain letters, and the length of each word.
The player can also scramble the letters to make it easier to see potential words. That said, using this option can cause more burning tiles to appear in the columns.
