Sure, here's an example of a lava-themed card game implemented as a single HTML file using JavaScript:
Lava Card Game
In this example, the game consists of flipping cards by clicking on them to find matching pairs. The cards are represented by pictograms related to the lava theme. The goal is to match all the cards and a message is displayed when the game is successfully completed. The game works on a smartphone or any other device with a web browser.