Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
An abstract web texture of a polished blue stone (or does it look more like ice).
Source V. Hartikainen
This background pattern has futuristic look. So, maybe it could be used on websites or blogs dedicated to video games?!
Source V. Hartikainen
Prismatic Isometric Cube Wireframe Pattern No Background
Source GDJ
Bright gray tones with a hint of some metal surface.
Source Hendrik Lammers
A repeating graphic with ancient pattern. I came up with this name/title at last minute, so you may find that there is very little of ancientness in this pattern after all.
Source V. Hartikainen
A seamless background tile of aged paper with shabby look.
Source V. Hartikainen
Imagine you zoomed in 1000X on some fabric. But then it turned out to be a skeleton!
Source Angelica
It looks very nice I think.
Source V. Hartikainen
It’s a hole, in a pattern. On your website. Dig it!
Source Josh Green
Inspired by a 1930s wallpaper pattern I saw on TV.
Source Firkin
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
A seamless pattern formed from cross 4. To get the original tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Horizontal and vertical lines on a light gray background.
Source Adam Anlauf
Pattern that came out of playing with the 'slinky' plug-in for Paint.net
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless pattern created from a square tile. To get the tile, select the pattern in Inkscape and use shift+alt+i.
Source Firkin
Got some felt in my mailbox today, so I scanned it for you to use.
Source Atle Mo
Remixed from an image on Pixabay, the original having been uploaded by darkmoon1968.
Source Firkin
Some dark 45 degree angles creating a nice pattern. Huge.
Source Dark Sharp Edges
Prismatic Abstract Geometric Background 4
Source GDJ