Certainly! Here's an example of an incremental game implemented as a single HTML file with JavaScript code enclosed in `` tags:
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A TV
A ZOMBIE ONE
In this game, the player can click the "+1" button to increment their score by 1. They can also click the "Upgrade (+10)" button to spend their score on upgrading the score increment. Both the score and upgrade cost are displayed on the page.
Note: This is a minimal example to demonstrate the basic structure of an incremental game. You can enhance and add more features to make it a fully-fledged game according to your requirements.