Sure, here's an example of an HTML game that fits your requirements. This game is a simplified version of the game you described, where you control Flandre Scarlet and try to avoid getting caught by Sakuya while running down the hall.
To use this code, you'll need to provide an image file named "emozi_cat.png" that represents Flandre Scarlet. You can replace it with any suitable image you have.
When you load this HTML file in your web browser (preferably on a smartphone or emulator), you'll see a game container with an image of Flandre Scarlet and a text indicating the game is in progress. When you press the spacebar, Flandre will start running down the hall. After three seconds, she will pretend to play with toys, acting as if Sakuya is looking. If you don't press the spacebar in time, the game will end and display a "Game Over" message.
Please note that this is a very basic implementation of the game and can be improved with additional features and visual enhancements. It's also important to ensure the use of appropriate images or pictograms, respecting any copyright or licensing requirements.