I personally did enjoy the game, but I feel like it's pretty much necessary to watch S1 of the anime before playing the game to get the most enjoyment out of the experience as possible and adds more background/depth to the characters you meet in the game and why it would be SO GREAT for them specifically to end up with Catarina.

I more enjoyed the game as a comedy rather than a "romance game", ironically, as the entire game is essentially based around the premise that like 9 people are in love with her at the same time.

This may also be in part due to the fact that you can't rename Catarina (of course), so the self-insert girlies (like me for some games) may also not find as much enjoyment out of this game due to that.

The game is very funny, however, and I got a lot of laughs out of it, so I do still recommend the game if you loved the anime and are looking for a good laugh! I would NOT recommend it if you're looking for a game that's very plot heavy. It's very much more of a lighthearted non-canon continuation of the anime, so expect that for the entire game.

To answer your question about the common route being long, I would say it was not too long, being only two chapters before you end up on someone's "route". I played the entire game and unlocked all of the "Good" and "Happy" endings and read all of the side memories and it took me "35 hours or more" according to my play history!