trout yogurt

3

Negative man is like Napstablook.

So many Earthbound references. “but nobody came” is what it says in Earthbound when enemies call for backup but no more enemies show up, in the cut out battle with RG03 and RG04 they say they are going to get salmon flavored ice cream, a reference to the trout flavored yogurt in Earthbound.

then theres the entire true lab which is a homage, and the music has many samples of Earthbound music, which itself has all the samples here.
https://www.youtube.com/watch?v=E_oc9Ypcb2Q

Theres also Gigyas and Photoshop Flowey, and a few more storyline and musical based things can be found here https://www.reddit.com/r/Undertale/comments/3n9e5u/spoilers_post_all_similarities_to_earthbound_here/