Hi Everyone! Sorry for the late response! I was busy travelling (and writing) the last month, as well as investigating all the new titles that came out for ideas (Pokemon, RF, Hometown Story, and more), and boy have they inspired ideas!
With regards to your question about the features, and as to what is outside the box, I'm not very sure how to answer that...as Solid Snake is rather using it to sneak around and save the world and whatnot.
Seriously though, when I conceptualized the game, I wanted to hold on to that classic Harvest Moon "feeling" and experience, but I also wanted something..."more", so I'll do my best to describe that

.
In actuality its probably a lot of little things that we're doing, that as a whole ammount to something awesome, so I'll start.
Story - I would say one of the keystones of the game would be the stories we are trying to tell. As mentioned earlier, we are going for a slighly darker and more mature theme. Aside from the town's dark secret, the characters themselves have individual conflicts that they need to overcome. These can be minor problems such as heartbreak, to overcoming a drinking or addiction problem (not substance abuse! We'd probably have to get rated M for that and we're trying to avoid it >.< (at least at this stage).
Activities - We're trying to introduce more activities, that are impacted by your decisions. Things beyond just the usual produce fairs. We want to emulate something akin to Golden Saucer from FFVII. Particularly the chocobo functionality.We hope to be able to do something similar with the dogs and horses, allowing you to become a master breeder, if that is your fancy. It does not end there. We are playing around with a few other things you can do on the side as your "focus" beyond farming and raising animals for crop
Automation & Machinery - This could be tricky, but we want to introduce easier farming thru machinery
Cellphone - As GTA recenlty introduced, the cellphone can be an excellent way to communicate with NPC's. However what you can do with your phone will change over time, as how the town's cellphone network and its features evolve, will depend on your interactions with the towns folk
Mayoral Elections! Become Mayor - This is something we really really really really want! Although I really dont know if it will make it to the final game (funding dependent), but we're still deciding on the mechanics for this, and how it will affect the town (it may be a DLC)
Crowdsourced beauty competitions - Inspired by pokemon. But instead of haivng your farm animals rated by the system, we will let people decide!
crop trading - with region based crop availability (based on your region you will have different crop selections available to you, encouraging trade)
dating - As mentioned previously we wanted to go overboard with a relationship and dating simulator. We've made a relatively large world with lots of options to take your desired partner on dates as you try to romance him/her, and even locations to propose!
After Marriage life - We also want to make your wife (and kid/s) more involved in life beyond marriage. Depending on who you choose, your partner might be fiercely independent, bossy, or needy. This will affect your post marital relations as we want your partner to do more than sit at home with your kid.
Quite honestly this is just the tip of the iceberg of what we WANT to do. We have lots more planned, but as mentioned previously how far we can go will depend greatly on funding, although we have our fingers majorly crossed that we'll get enough to do everything (and we're praying we hit several hundred thousand dollars at least so we can really, not just make the best game we can, but also have enough to keep us in business beyond that making more awesome games, as we are just as excited for our next IP too :D, but one thing at a time ^^ )
We intend to hopefully launch our kickstarter this friday (so please set some money aside for us :D), and next week we'll do an AMA on Reddit. So please have your questions ready! :D, although for you guys, I want to preview the trailer here before we send it out to the world, and you guys will get first crack at our proof of concept demo before we decide to reveal it to trhe world, just because you guys have been so awesome!