About Mario 4: A Space Odyssey
In Mario 4: A Space Odyssey, the plot has Mario and Luigi watching the stars until a star crashes onto the ground. An Alien creature (despite the intro depicting multiple Shroobs from Mario and Luigi: Partners in Time, the text only states one) warns Mario and Luigi about an oncoming threat and that they need to stop the conqueror of galaxies with their army. (However, in-game there is no army that fight alongside Mario and Luigi).
There's only a total of sixteen levels in the game. The enemies are completely different; being mostly a combination of Shy Guys, Bob-Ombs, Shroobs and giant versions of Goombas and Piranha Plants. There is a 2-player option where the second player plays as Luigi. You can also access a shop by pressing C when you pause. You can buy Super Mushrooms, Fire Flowers, continues and extra lives.
After the final level, you fight what appears to be a giant, black version of Fawful's head. The graphics this time around not only use graphics from Super Mario All-Stars but also Super Mario World 2: Yoshi's Island and New Super Mario Bros.
The continue and game over screen has become infamous for the same reasons as Mario 3: Around the World's and they're both stolen. The continue screen is based on a t-shirt design known as Game Over by Aaron Wiliams. The game over screen is based on another t-shirt design called Original Gamer by Dann Matthews. The music and sound effects remain the same.
Source : Fandom.com
Game Controls
← → ↑ ↓ = Move
Enter ↵ = Start
Space = Select/Mode
Z = A
X = B
C = C
A = X
S = Y
D = Z