Games like Exterminant
Games like Exterminant include Vampire Survivors, Cookie Clicker, Chillquarium, Keep on Mining!, and Shelldiver. We matched them by the tags players give Exterminant on Steam (Casual, Arcade, Collectathon, Creature Collector, and Idler): closest matches first, and among equally close ones the better-known games.

Vampire Survivors
Shared: Roguelite · Casual · 2D

Cookie Clicker
Shared: Casual · Idler · Collectathon

Chillquarium
Shared: Collectathon · Creature Collector · Idler

Keep on Mining!
Shared: Casual · Idler · Arcade

Shelldiver
Shared: Casual · Arcade · Idler

Nodebuster
Shared: Casual · Arcade · Idler

To The Core
Shared: Casual · Arcade · 2D

Tiny Aquarium: Social Fishkeeping
Shared: Collectathon · Creature Collector · Idler

Timberman
Shared: Casual · Arcade · 2D

Melvor Idle
Shared: Casual · Idler · 2D

Megabonk
Shared: Roguelite · Arcade · Indie

Planes, Bullets and Vodka
Shared: Casual · Arcade · Action

UFO 50
Shared: Arcade · 2D · Retro

Cyberhunt
Shared: Casual · Arcade · Action

Rogue Legacy 2
Shared: Arcade · Roguelite · Action

BALL x PIT
Shared: Arcade · Roguelite · Action

Bills Must Be Paid
Shared: Roguelite · Casual · Idler

Kabuto Park
Shared: Casual · Creature Collector · Nature

Keep on Mining! - Worlds
Shared: Casual · Idler · Collectathon

Desk Paws
Shared: Casual · Creature Collector · Idler

Scritchy Scratchy
Shared: Idler · Arcade · Roguelite

Shower With Your Dad Simulator 2015: Do You Still Shower With Your Dad
Shared: Arcade · Casual · 2D

Streets of Rage 4
Shared: Arcade · 2D · Action

Bugtopia
Shared: Collectathon · Idler · Creature Collector