I put together a collection of itch.io pages that I thought were pretty well designed. Hopefully if you’re a gamedev you can get some ideas of what to do for your own page. Some of them look fancy, but really the colour scheme, font, and background choice go a really long way to encouraging people to stick on your page long enough to read the description, or watch a video.
If you’re not a game developer you can still take a look, some of the pages lead to some cool games. :)