As an AI text-based model, I can provide you with a game concept that fits the requirements you have outlined. Below is an example of a simple game called "PictoMatch" that can be implemented as a single HTML file, containing JavaScript code enclosed in script tags.
PictoMatch
Score: 0
Choose the matching pictogram!
This HTML file contains a simple game where children can click on the pictograms displayed on the screen to match a target pictogram. The score increases when a correct match is made, and a new target pictogram is displayed. The game uses pictograms as symbols and implements basic game logic to provide engagement for children.
Note: This is a basic game concept, and you can modify, enhance, or customize it further according to your specific needs and preferences.