Simplify the following text for a Grade 4 native English-speaking person.
Original: Mario 's occupation is plumbing , though in the original Donkey Kong games he is a carpenter . Mario has had several other occupations : in the Dr. Mario series of puzzle games , which debuted in 1990 , Mario is portrayed as a medical physician named `` Dr. Mario '' ; in the Game Boy game Mario 's Picross , Mario is an archaeologist ; and in Mario vs. Donkey Kong 2 : March of the Minis , Mario is the president of a profitable toy-making company .
Simplified: In Mario vs. Donkey Kong 2 : March of the Minis , it is said that Mario has a toy-making company that earns him money .