Games like Spacelair
Games like Spacelair include Banana, DAVE THE DIVER, Home Behind, The Scroll of Taiwu : Beyond The Dome, and Stardew Valley. We matched them by the tags players give Spacelair on Steam (Casual, RPG, Side Scroller, Simulation, and Sci-fi): closest matches first, and among equally close ones the better-known games.

Banana
Shared: Casual · Singleplayer · Simulation

DAVE THE DIVER
Shared: Casual · Adventure · RPG

Home Behind
Shared: RPG · Casual · Adventure

The Scroll of Taiwu : Beyond The Dome
Shared: RPG · Simulation · Casual

Stardew Valley
Shared: RPG · Simulation · Casual

Touhou Mystia's Izakaya
Shared: Casual · RPG · Simulation

Melvor Idle
Shared: RPG · Casual · Adventure

My Time at Portia
Shared: RPG · Casual · Simulation

Graveyard Keeper
Shared: RPG · Simulation · Singleplayer

To The Core
Shared: Casual · Adventure · Incremental

鬼谷八荒 Tale of Immortal
Shared: Simulation · RPG · Singleplayer

Dragon Cliff
Shared: RPG · Casual · Adventure

Papers, Please
Shared: Simulation · Indie · Singleplayer

Emily is Away Too
Shared: Simulation · Casual · Indie

That's not my Neighbor
Shared: Casual · Adventure · Simulation

Vampire Survivors
Shared: Casual · Singleplayer · Indie

Evoland
Shared: RPG · Adventure · Retro

UFO 50
Shared: Retro · RPG · Indie

Potion Craft: Alchemist Simulator
Shared: Simulation · Singleplayer · Casual

To the Moon
Shared: Adventure · Indie · RPG

Endless Sky
Shared: Sci-fi · Simulation · RPG

Plebby Quest: The Crusades
Shared: Casual · RPG · Simulation

Weapon Shop Fantasy
Shared: RPG · Simulation · Casual

Shovel Knight: Treasure Trove
Shared: Retro · Adventure · Indie