I've been through all routes except Adams within Backstage Pass, probably played around 30 hours, maybe a bit more. But if you've got any reservations you could wait for a sale it occasionally gets discounted by 25% but it was -45% during the recent summer sale. I think it is worth it at full price if you don't mind stat-raisers, especially since it's fully voiced and on the whole a high quality game. There are also a bunch of non-romantic endings.

There's also 2 other romantic routes and a friendship route - I'll name who they are: the friendship route is with Lloyd, the romantic routes are with Nicole or Alvin. The main love interests are Adam, John, Benito and Matthew. Even if you're on a romance route, you still spend a lot of time stat-raising and possibly doing jobs and befriending other people.

I'd say it is heavier on plot than romance, but on the romantic routes the plot ties into the romance so it's usually ok. Not sure about length of each playthrough but I got about 28 hours of play from the game in total, finishing all routes and endings and with heavy use of the skip read text option. Personally, I really liked Backstage Pass (particularly John's route), but there was a noticeable drop in my enjoyment after my first playthrough because some events are repeated through routes and the stat-raising started to wear a little thin.

Backstage pass game alvin