Games like Space Trade Fleet 1.5
Games like Space Trade Fleet 1.5 include Caster, Juicy Realm, Dead Bits, Freeman: Guerrilla Warfare, and The Ascent. We matched them by the tags players give Space Trade Fleet 1.5 on Steam (Indie, Casual, Action, RPG, and Shooter): closest matches first, and among equally close ones the better-known games.

Caster
Shared: Indie · Action · Casual

Juicy Realm
Shared: Indie · Action · Casual

Dead Bits
Shared: Indie · Casual · Action

Freeman: Guerrilla Warfare
Shared: Action · Shooter · RPG

The Ascent
Shared: RPG · Action · Indie

BioShock Infinite
Shared: Action · Shooter · RPG

Borderlands 2
Shared: Action · Shooter · RPG

My Friend Pedro
Shared: Indie · Action · Shooter

KovaaK's
Shared: Action · Indie · Shooter

Yokai's Secret
Shared: Indie · Casual · Action

G2 Fighter / 基因特工
Shared: Indie · RPG · Action

Cat Quest
Shared: RPG · Action · Indie

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

Lost
Shared: Casual · Indie · Action

SUPERHOT
Shared: Action · Indie · Shooter

How to Fish
Shared: Indie · Shooter · Action

Bladed fury
Shared: Indie · Action · RPG

ShellShock Live
Shared: Action · Casual · Shooter

Melvor Idle
Shared: Casual · Indie · RPG

Hades
Shared: Indie · Action · RPG

UFO 50
Shared: Indie · Action · RPG

Vampire Survivors
Shared: Indie · Casual · Action

Bastion
Shared: Indie · Action · RPG

Notes of Soul
Shared: Action · Indie · RPG