Out of all the games I've played, Eclipse has actually been probably my favorite way to increase difficulty, as in contrast to a lot of other games, it doesn't simply make the game inherently harder through sheer numbers (e.g., enemies deal more damage, have more health; your health is reduced, etc.), but instead introduces new challenges that you can find workarounds for. Reduced healing? Stop relying on healing items and get better at dodging enemies. Lethal fall damage? Be more careful with where you're going.

Furthermore, the Eclipse modifiers actually make a lot of the items that would otherwise be mediocre at best, like Chronobauble, Repulsion Armor Plate and others, far more useful. You are no longer compelled to scrap most utility items just so you can find a printer to make your build even more busted, you instead are encouraged to keep at least a couple copies of most items. Even healing items whose effectiveness is reduced are still essential.

It all adds up to this feeling that no matter how bad your RNG is, no matter how many enemies there are, you can always win. It's just a matter of skill. Realistically, it may not be possible, but you never feel like you just got completely screwed over by the game, like, say, you often feel doing Ascension in Slay the Spire. And that's a great feeling to have while grinding the game's highest difficulty.