I think it could be a great asset to add a log in pop up with Tips and/or update about the game.
Much like other games from Nutaku (or any other games for that matter) giving Tips and news about a game can be very useful for new comers and veteran alike.
For Harem Heroes it could be things like;
- Do you know that you can "free" girls from the Dark Lord to add to your Harem?
- The Tower of Fame is now live and you can compare with other players
- You can keep on watching girl affection cut scenes by clicking on her stars in her file
- Duel other players to earn Mojos which is usefull to climb up the Tower of Fame
- Have a question about the game, how about looking for the wiki?
- Today we have a major update with world xxx and of course ton of Girls to meet
and so on...
I am pretty sure this could boost the interest of the game.