Well, if you don’t like 2D fighters, there isn’t much I can say to convince you, but a lot of the endings are up on YT, usually with a translation. So you can at least watch those and not have to play the game. You won’t miss much except maybe an idea of what ifs for different stories. Sadly, not everybody has a story mode with every other player (I’d love to have a story for Erika/EVA, Bern/Ange, Lambda/Beato).
The routes if one has the full Cross Expansion are: Beato/Battler, Beato/Ronove, Beato/George (a kind of joke end), Beato/Virgillia (joke end), Beato/EVA, Beato/Lucifer, Battler/Ange (MY FAVORITE), Battler/Lucifer, Battler/Kanon, Battler/Ronove (one of many joke RonoBato ends), Black Battler/Sayo (it’s Shannon but the story makes it clear who she’s meant to be), Battler/Rosa, George/Jessica, possibly Shannon with others I’ve never seen her routes translated except the B Battler one, Jessica/Kanon (joke end), Jessica/Lambda (a fun one not so much a joke), Virgillia/Dlanor (another special joke end), Virgillia/Ange (these dang joke ends), Rosa/EVA (a definite joke end), Rosa/410 (jokes), Ange/Lucifer (jokes everywhere), Ange/EVA, Ange/Erika, Lucifer/410 (joke end), EVA/410 (joke end), EVA/Ronove, Erika/Dlanor (it’s joke), Erika/Bern, Bern/Lambda, Bern/Will (serious even if the pic is a joke), Lambda/410 (IT’S JOKE), Will/Dlanor, and those are all the ones I’m aware of.
Every other pair just puts you in arcade mode, which can unlock some really interesting dialogue. Black Battler’s is of course twinges with lust and bloodlust towards EVERYONE AND I MEAN EVERYONE except Erika, who just gets a “BOW DOWN TO ME AND KEEP CRYING.” Thing towards her.