Thanks for playing – and for the review! Really glad to hear you enjoyed it (and it sounds like you found all the hidden details!).
And yes, there are definitely inspirations from other games – such as The Persistence and Prey (and System Shock, which inspired them).
the third item
The third item for that last puzzle actually starts off floating around exactly where you need it, but some folks recycle it without realising! If that happens, it respawns somewhere else.