I'm glad you enjoyed the game!
With limited art availability and my amateurish coding skills, the writing was really all I had going for me. I cut a lot of corners in the art and the visuals, grudgingly saying "this looks bad but it's the best I have without dumping ten thousand dollars into this" a whole lot, but I didn't let myself wimp out on the writing. I have "write" in my name, god damn it.
With the main mission involving Cynthia, it never really occurred to me that the game should also have sidequests with her too. I intentionally made the evening activities with Jasmine and Betsy and the wilderness stuff with Kate be a little divorced from the main story, to give the player sort of a break from sleuthing with Cynthia. But now that you mention it, the game probably should have had some fun little side-things you go off and do with Cynthia too. I'll keep that in mind for future games. I'm happy to report that the next game has a whole bunch of side missions with the main girl.
You're right that the game might be better if it focused more on Cynthia then on the supporting characters. Kate and Betsy actually weren't planned to be in the game at all when I first started writing it. Betsy sort of arose out of the necessity to have a primary villain, and I wanted the player to be able to run off and join the bad guys so we could see Cynthia as an obstacle under certain circumstances. That means the leader of the bad guys kind of had to become a proper character. Kate I have no excuse for. The existence of the pokemon rangers started as a throwaway joke at the start of the game, and it was only later when I decided it might be interesting to go and visit them. Then Kate's presence in the game kind of grew like a metastasizing tumor. I don't regret her being in the game, but you're absolutely right that there are a lot of non-Cynthia distractions in a game that bills itself as "hang out with Cynthia!"
As far as the game's visuals... yeah, they're all bad. The lewd scenes look okay, obviously, since I had real artists drawing them. For the rest of the game though, this is sadly the best I was able to do with no budget for the game. I can tell you my next game is going to look a lot better because I have a better idea of what I'm doing and I have more money at my disposal to throw at the project. In the future I would like to remake Olivine Lights entirely with better art and graphics for... everything, and maybe add some more content to it. A sidequest or two with Cynthia. More sex. Better pokemon battles. Proper character sprites. Art for characters sitting down. Backgrounds that aren't photos. Et cetera. That won't be for a long time, though, and it will cost money. The fear of legal trouble from Big N prevents me from charging for this game, so unless I find a schmuck of an artist who's willing to draw stuff for me for free, art is probably going to continue to be the weakest thing I have going for me.
One last thing... I'll be honest, I have no idea what you mean by the suspension bridge effect.