Oh hey newbie! I'm so glad that you got to try out the game before spoiling yourself too much!
I played the demo first and I actually bought the game the day it came out and finished it in one sitting.
At the time literally everybody was playing blind. We didn't know any of the game mechanic- or just what kind of game this was in general. We just jumped right in and man... I'm pretty sure those people are still struggling in undertale hell like me. I thought I'd get over it soon.. but... It's been more than 6 months and still here I am, lurking in subreddit every day, collecting artwork, upvoting amazing musics and sometimes producing my own work. I'm not an artistic person. I've never drawn anything worthwhile in my life, ever. But this game.. It changes you.
But what's most incredible is that because of the game, you learn to look at things at a different perspective. You slowly realize the reason behind some of the character's action as you live your life and find a little piece of them in you. For example when you screw up big time and feel too scared to face the consequences, you will recall a particular moment in the game when you've harshly judged a certain character for its actions. You'll remember the moment you've given that person the courage to move forward and it will help you understand that however harsh the consequences may be, it will only get worse when you hide it.- and you are filled with determination to move forward.
That's the moment.
That's the moment that you realize that undertale is a great game. When you realize a freaking 16 bit indie RPG touched your heart and helped you become a better person. When life is shit and someone's giving you a mighty kick at the ball, and you remember Flowey's favorite phrase: "It's kill or be killed". But now you know better than to pass those hate around. Although it may not work, you will try to bring out the best of people by being kind to them. Although those people may seem like a monster, when you listen to them, you will understand what they are going through and maybe help out if you're feeling extra generous. Then, your enemies in life doesn't seem so terrible anymore, so and so forth.
...Well, I just wanted to say hi then ended up writing an essay. So maybe I'm looking at this too deep, finding meaning where it doesn't exist. Maybe I'm just a hopeless fanboy clinging to one game for too long. Maybe some people like the game because blue flaming eye is a thing now. But at least for me, this really was the best game of my life and since you've shared your feeling of the game so far I guess I just wanted to share mine with you!
So.. yeah, the game doesn't end with the ending. It melds into your soul and slowly consumes your life.. until you become a filthy undertale trash :3 like me! So have fun playing- and let us know your thoughts on further development! We rarely have new players around here anymore so this was super fun to read!!