Just want to confirm but can I make a game that's not exactly an otome game but still incorporates the same concept in some part? For example, something like Riviera:The promised Land or Harvest Moon:Friends of Mineral town?
I am a little confused by what you mean. But as long as the game has a male playable with romanceable heroines, has no adult content, and has a minimum of two endings, then anything is fine. If you are asking if you are able to make an RPG game with the ability to romance, that is totally acceptable. ^^
EDIT: I just realized taking into account your examples, are you asking if you can submit a game that has the option of playing male or female, and is basically a bishoujo game when male and an otome when female? If so, I see no issue with it. So long as you can play a male MC with romanceable females, I see no problem with the available option to play in reverse. ^^
Even if your game is free, it's not good to use copyrighted music. There are plenty of websites that offer free to use tracks.
I recommend these;
https://soundcloud.com/alcaknight most music here is available to freely use in VNs with credit
http://slos.biz/ for rules on usage, just click the top right corner "for English simply put", you are free to use so long as linked to http://sentive.net/ and they have a report form to fill in (they like to know what projects their music is in, that is all)
http://www.hmix.net/ of course credit