there is a game based on vocaloids, but originally its a program.
Probably utauloids
There are a lot of VOCALOIDs. VOCALOIDs are now up to at least 45, and their are more than 60 voicebanks.
No. VOCALOIDs are not couples. VOCALOIDs do not have to deal with anime or couples. It's only a singing program.
yes
There is no any other VOCALOIDs. All vocals found in VOCALOID wikia are the original VOCALOIDs made buy actual music/recording companies. Haku Yowane, Akita Neru, and Hatsune Mikuo etc. are fanmade based of the VOCALOIDs voicebanks.
around $200
Utaloid is a subcategory of Vocaloid software, with an emphasis on Japanese-speaking virtual singers developed by a specific company. Vocaloid refers to a broader category of voice synthesizing software that can produce singing by inputting lyrics and melodies.
Every VOCALOIDs have diffrent prices. The cheapest VOCALOID is currently $40 dollars and the highest price is about $400. You can buy the VOCALOIDs in their company's website.
To me i think Vocaloids did
depends on which one you buy. Luka is bilingual and can sing very well in english., and all the vocaloids can sing in english, but you can barley understand them.
Well, if your going in chronilogical order it goes: First generation vocaloids (MEIKO, KAITO, ...etc) Second generation vocaloids (Miku, Rin, Len, Luka...etc) Utauloids or UTAU's (Teto, Neru, ...etc)