(Originally posted on Tumblr)
I may write a proper essay to elaborate my thoughts on this subject better, but for now, I want to state for the record that I actually like the ending of Cassette Beasts and I think it fits the story and theme of the game.
Yes, it is bittersweet, but it is not a bad thing. A story being happy, sad or bittersweet does not inherently make the ending good or bad; what matters is how well the ending is set up, and how thematically fitting the ending is to the story. In my opinion, the Cassette Beasts ending achieves both.
Cassette Beasts' story has set up from the very beginning that the player character's goal is to find a way to leave New Wirral, and that the people who are living in New Wirral, including all the player character's partners, came from different worlds, with no one knows how to go back to their world until the player character and their party do in the ending. It makes sense that the player character's party expect they may never see each other again, because the game never says if there is a way to contact with someone else from a different world.
Even if you choose to romance a partner, every single romance option points out that you may have to split up when you return to your own worlds during their conversation where you choose to commit a romance with them, but they all also state that despite that, the time you spent together still matters (see my video compilation of the partner romance scenes). Not to mention, every partner has their own life before arriving at New Wirral, and it is neither realistic nor healthy to expect them to give up everything they knew in their world just for one person, even if you are the protagonist. So it makes sense that you and your romance option do not stay together in the ending, but that does not mean there is no point in romancing them.
Morgante says outright during your final battle against Aleph Null that humans have the ability to manifest their will to alter reality, to change the world and themselves, to the extent even cassette tapes are merely talismans to channel that will, which is proven immediately after when the player fuse with all their partners even though their cassette player was broken. Kayleigh echoes Morgante's words in the ending when saying goodbye to the player character that they do not need cassette tapes to manifest their will to change the world. Combined with the partner characters' growth during their time with the player character, the game opens up the hope the party can take what they learn from their time in New Wirral to make their lives better. This is the game's another way to reaffirm that even though you and your partners' stay in New Wirral may not be permanent, it does not mean your time in new Wirral does not matter, and returning to your world does not necessarily mean returning to the status quo either.
Cassette Beasts' story is not a choice-driven narrative (which is not a bad thing since not every game needs to have one); even choosing to pursue a romance with a partner does not change the story and just add some additional dialogue when you rest and a few extra lines in the ending (which is a good thing because I dislike it when the story or a character's "best" ending is locked behind a romance), so I am fine with the lack of option for the player to not returning to their world. That said, there is also an argument to be made that you, the player, choosing to continue to play the game, including the post-game is deciding that you still want to stay in New Wirral. Even Ms. Amber says after you defeat Aleph Null and discover the gateway to leave New Wirral that you do not have to leave right away. In that sense, the game's ending also serves as your farewell to New Wirral as the player.
I do not know if liking the Cassette Beasts ending is an unpopular opinion, because there is a possibility that not liking the ending is a case of vocal minority, but they are still vocal enough that I am compelled to write this post to defend the ending.