Awesome Music: The Power Stadium arena has a remix of the Standard Match theme from Power Pros 10, which is one of the most catchy and energetic in that franchise.
More than a decade later, Simon also appeared in Super Smash Bros. Ultimate, making it the second game where he could face Snake in a four-player party brawler game. Bonus points for having the same seiyuu as in this game!
Hudson's properties eventually became owned by Konami, so Bomberman also shows up in Ultimate, albeit as an Assist Trophy and DLC Mii costume instead of a playable fighter like the above mentioned two.
Power Pro-kun was eventually added to Ultimate as a sticker.
Just Here for Godzilla: Most who know of the game only want to try it on the basis that it's a game where Optimus Prime can fight some well-known Konami characters.
Unexpected Character: Pretty much everyone, but given his particular nature, Moai (who's only a flying head) is surely strange.