Hey Cheese,
1. What OS are you using? (Windows/Android/Mac/Linux)
2. If It's Android, What Device?
3. If It's Windows: did you make sure to extract it to a separate folder (out of the zip) before playing? As well as running as administrator?
4. Did you try making sure nothing runs in the background while playing?
5. Do you encounter an error when it happens?
6. Maybe if you have enough time in the 3 seconds, to run into the settings in the main menu and change things there (Like toggling off Post-Process effects)
Let me try to narrow down the problem