Bold and Eye-Catching: The thumbnail should be visually striking and immediately capture the viewer's attention. Use bright and contrasting colors to make the thumbnail stand out.

Relevant Image: Use an image that is directly related to the topic of the video. This could be a screenshot from the game or a character from the series.

Clear Text: Include text on the thumbnail that clearly indicates what the video is about. Use a legible font that is easy to read even at small sizes.

Consistent Branding: Use the same font, color scheme, and overall design style for all of your Contra videos to create a cohesive brand.

Action-Oriented: Use dynamic and action-oriented imagery that communicates the excitement and intensity of the gameplay. This will entice viewers to click on the video and watch it.

High-Quality: Make sure that the thumbnail is of high quality and resolution, as blurry or pixelated images can turn off potential viewers.

Unique and Creative: Try to come up with a unique and creative design that stands out from other Contra videos. This will help your video get noticed and attract more views.