Upon losing to the final boss, you get kicked back to earlier in the game, not necessarily in identicality to initially proximal state: farther back based on doing lousier.

A common theme is grinding up abilities and stats for the final hoo-rah; if you don't succeed then game over, if you do then rewarded cutscenes and credits.

Well what if failing to secure victory (and thus concluding that run of the game) resulted instead in kicking you back, but not to merely the last checkpoint but probably farther, roughly proportional to how close you got.

There is different ways this and degrees of complexity to which this could be implemented. At a more sophisticated end of the spectrum, your decisions within that particular battle (or whatever form the final no-saves stretch takes) could impact qualities upon your 'reset': for example, more attacky then perhaps given a relatively high-er Attack stat, if more spellcast-y then more magic mana (or equivalent), and so-on proportional far back to what percentage of what stage you made before dying (or otherwise failing to beat the final stage).

There are countless ways this could be bound to the storyline arc. Conceivably a multiverse-esque concept could tie-in.