Tests are pretty solid. Not brain dead easy, but easy, and look good.
Unique mechanics are cool.

Story is a bit confused. It's nice enough, and keeps you immersed.
I really don't like the ending though. . It's very clearly emulating Glados and Wheatley's dynamic, without fully understanding it.
Wheatley is revealed to literally be the biggest idiot possible by design, after ego tripping, and very clearly having evil tendencies.
Stirling, while yes, eventually trying to kill you, is just doing what he thinks is best. It's not clear whether he knows or understands what Glados did. Suddenly it's revealed he was originally a vacuum cleaner, and Emilia brutally dehumanizes him.
So what if he was? This just feels like an underdog story where you'd root for Stirling, but nope. You defeat him, and Emilia doesn't care at all what just happened. No remorse or second thoughts, just worry about what happens next.

Either, make him a proper villain; Make him not care for human life, or make him value fixing the facility above all else, despite any attempts at convincing.
Or, keep him semi innocent, and make Emilia sorry for having to kill him.
Or I guess lean into Emilia being oddly heartless.

This just feels empty and inhuman.

[b]Tests[/b] are pretty solid. Not brain dead easy, but easy, and look good. Unique mechanics are cool. [b]Story[/b] is a bit confused. It's nice enough, and keeps you immersed. I really don't like the ending though. [spoiler]. It's very clearly emulating Glados and Wheatley's dynamic, without fully understanding it. Wheatley is revealed to literally be the biggest idiot possible by design, [i]after[/i] ego tripping, and very clearly having evil tendencies. Stirling, while yes, eventually trying to kill you, is just doing what he thinks is best. It's not clear whether he knows or understands what Glados did. Suddenly it's revealed he was originally a vacuum cleaner, and Emilia brutally dehumanizes him. So what if he was? This just feels like an underdog story where you'd root for Stirling, but nope. You defeat him, and Emilia doesn't care at all what just happened. No remorse or second thoughts, just worry about what happens next. Either, make him a proper villain; Make him not care for human life, or make him value fixing the facility above all else, despite any attempts at convincing. Or, keep him semi innocent, and make Emilia sorry for having to kill him. Or I guess lean into Emilia being oddly heartless. This just feels empty and inhuman.[/spoiler]