Learn Finnish: Käytettäisiinköhän uutta pelimekaniikkaa? - I wonder if the new game mechanic would be used?

It starts with the verb stem käyte-, adds the passive voice marker -ttä-, then the conditional mood marker -isi-, followed by the passive personal ending -in. Finally, we stack two enclitic particles: the question marker -kö- and the softening marker -hän.

Could I swap the two clitics at the end and say käytettäisiinhänkö?

No, enclitic particles have a strict internal hierarchy. The question marker -ko or -kö always attaches first, immediately after the personal ending. Softening or emphasizing particles like -han or -hän must come after the question marker.

How does the passive conditional differ from the active conditional here?

If you remove the passive marker -ttä- and adjust the personal ending, you get the active first-person form käyttäisinköhän (I wonder if I would use). The passive form käytettäisiinköhän focuses purely on the action (I wonder if it would be used) without specifying who is playing the game.

Since this is a passive sentence, shouldn't the object be in the nominative case instead of the partitive uutta pelimekaniikkaa?

Usually, passive sentences take a nominative object, but the partitive overrides that rule here. The verb käyttää naturally governs the partitive when meaning 'to use' in an ongoing, open-ended way. A game mechanic is an abstract concept being utilized, not a physical object being completely consumed or finished.