Overall

Vision Vision

Originality Originality

Technique Technique

Impact Impact

This might be just nit-picking, but maybe you could create a greater contrast between those at the front, (ie: Frisk, those on her head and Sans) just to make them stick out a little more. Maybe you could do this by making those behind them a little darker. The fact that they are all so colourful is very jovial and attractive, but the colours are all quite light, which is fine but conbined with the white outlining, it makes it a rather chaotic and confusing at first glance, especially with the flowers.Also I think the balance is a little off. If you moved the bulk of characters including Torial and Asgore down to fill that gap by the dogs neck, and so made that gap between the top and the bottom of the picture, it would satisfy my OCD tendencies and bring focus more to the centre with those in the front rather than splitting it with that gap. Creating the contrast would also help guide the attention and make it more striking.I am a bit too lazy to rate this properly, but I think it is a very detailed, beautifully coloured and skillfully drawn piece with great energy. I've seen similar consepts for Undertale with everyone floating through colour bombs and looking happy etc... Even I've kind of drawn one of them, though it had more of a theme, so while I can't give you a lot of points for originality of the basic premise, all of the artists I've seen do this, including yours, have had great composition and beautiful art, and are definitely their own. The characters look great and faithful to the game... except for Sans's tongue. Please remove Sans's tongue.