Spamton draws a number of parallels to Mettaton from Undertale throughout his character arc in Chapter 2:

• Both characters have names ending in "-ton", and both Spoiler:have NEO forms that can be optionally encountered. Speaking with Swatch after Spoiler:defeating Spamton NEO on the normal route implies that Spoiler:the robot that became Spamton NEO's body was designed by Deltarune's equivalent of Mettaton.
• Both characters speak in all-caps with idiosyncratic speech patterns (staggered text scrolling for Mettaton, random bracketed text and typos for Spamton).
• The purchasable Spamton-shaped mannequin in Cyber City wears the same dress Mettaton does during the latter's opera performance.
• Before fighting him on the Neutral and Pacifist routes in Undertale, Mettaton makes a statement that appears to align with the protagonist's goals before quickly responding with "NOT!!!" Spoiler:On the Weird Route in Deltarune, Spamton NEO makes a similar jab, even using the exact same formatting for the "NOT!!!" response.
Spoiler:Both Spamton NEO and Mettaton utilize similar mechanics in their fights. Both are fought using the Yellow SOUL, both include miniature versions of themselves with their own attacks, both use identical cross-exploding bombs, both feature attacks where the player must shoot their hearts (which fire back in turn), and both fights involve a free turn for the player (Mettaton EX taking a break, Spamton NEO being attacked by his own phone).
Spoiler:Spamton NEO's "Check" description reads "He's his own worst invention." This nods back to Mettaton NEO's "Check" description, "Dr. Alphys's greatest invention."
Spoiler:One line of flavor text in Spamton NEO's fight reads "The stage lights are shattered," nodding back to flavor text in Mettaton NEO's fight that reads "Stage lights are blaring."
Spoiler:Spamton NEO's battle theme, "BIG SHOT", samples Mettaton NEO's battle theme, "Power of 'NEO'".
Spoiler:Spamton NEO's ultimate attack on the Weird Route includes mock VCR HUD icons that read "WRECK" and "SPEW", nodding back to Mettaton EX's "REC"/"REW" attack.
Contributed by game4brains