Where the game lives
Unity projects are independent exports; Roblox projects are closely tied to the Roblox platform and community flow.
Unity vs Roblox
A comparison between a general engine and a platform-centered creation environment.
Recommendation: Pick Unity for broader engine learning. Pick Roblox if you want to publish and share inside the Roblox ecosystem quickly.
Speed to playable release
Roblox usually gets you to a shareable result faster.
Skill transfer
Unity is better if you want a more general engine skillset that transfers across many non-platform-specific workflows.
Audience feedback loop
Roblox is a strong choice when learning through social testing and platform-native publishing is part of the goal. Unity is stronger when you want your learning path to remain independent from one distribution ecosystem.
When not to choose it
Do not pick Unity only because it sounds more 'serious' if your real target is a Roblox-native game you want to publish quickly. Do not pick Roblox if your main goal is a broad standalone-engine workflow that should transfer beyond one platform.