Games like Idle Area 51

Here are some great alternatives to Idle Area 51 by PlaySide Studios :
Idle Anomaly: Alien Control
Idle Anomaly: Alien Control
★4.2
Find & Catch Alien UFO Games
Find & Catch Alien UFO Games
★4.0
Alien Flying UFO Space Ship
Alien Flying UFO Space Ship
★3.2
Unnamed Space Idle
Unnamed Space Idle
★4.2
Alien Raid: Monster evolution
Alien Raid: Monster evolution
★3.9
Space Bound: Planet games
Space Bound: Planet games
★4.4
Idle Space Mining
Idle Space Mining
★3.4
Merge Spaceship: Idle Space
Merge Spaceship: Idle Space
★4.0
Find the Alien - Alien Game
Find the Alien - Alien Game
★4.7
Operation: New Earth
Operation: New Earth
★3.8
Alien Sniper shooting game
Alien Sniper shooting game
★3.6
Xenowerk Tactics
Xenowerk Tactics
★4.6
Alien Guest: UFO arcade
Alien Guest: UFO arcade
★4.3
UFO RUSH : Alien invasion
UFO RUSH : Alien invasion
★4.0
Space Miner Simulator Game 3D
Space Miner Simulator Game 3D
★5.0
Alien Shooter
Alien Shooter
★4.0