Played through Undertale myself. It is very interesting and almost reminds me of an RPG Maker game called "OFF". Except, OFF's story is a complete enigma. Once you beat the game, you still don't know what just happened. I like how Undertale gives you the choice to spare every "enemy" you come across, and the game in of itself overall is very well written. I would gladly give the game a 10/10 as well.
You're not the first to compare it to OFF, interesting enough.
http://m.imgur.com/a/Plyyv