A simplified terrarium simulator where you take care of little critters, with very casual idle gameplay, you can have an active playstyle or check back in a day or so to see gains.

Fighting platformer game. Out of all characters avaliable, two of them are arthropods.

A parkour game of hazards where you play as web-slinging spider, using momentum and agility to swing around before any lava reaches you.

Play as a spider venturing through a mansion lot, with mysteries to solve about their owners and on the way spinning webs and hunting down insects. Notice: Locational services seems to be broken.

Widely-known and still impressive creature creator, can easily create some convincing arthropod-like creatures and wide empires of them.

Play as an anthropomorphic fly knight, insect-on-insect medieval melee combat nearly in same vibe as Mount and Blade with the aesthetic of Runescape. Spiders are enemies in this game.

Up-coming game. Contains arthropod characters of various levels of designs.

Don't Starve has Webber as a playable character, though lore says it's a kid fused with a spider that ate them. Otherwise, there are some passive arthropods and others hostile.

The adventurer mode for the current Steam beta and the classic version you can play as an animal person based on an arthropod, on the Steam beta you'll need to generate a world with a bug people civ.