Very impressive channel! Good video quality, audio quality, background music fits and is at a good level, thumbnails and channel have branding, and a well made trailer. You're on the right track.
The overall thumbnail image quality could use a bit of work. Like the Spreepicky Review thumbnail I think looks unique and eye catching. Just keep in mind the thumbnail image is what will hook someone in to watch your videos.
Your about page says new videos every second Sunday?
Banner icon looks ok, but the plain peach color in the background could say your uploading schedule.
Your videos need an outro. Outros should have a call to action "Subscribe to see more", and a watch previous videos links/thumbnails to help your channel grow.