I just downloaded the US Tamagotchi PC game from 1997 and dug into the HLP files to see if the voice actors in the game were credited. Mostly I was just interested in if the Tamagotchi had the same voice actors in the game as in Tamagotchi Video Adventures. I did find the voice acting list and it looks like at least some of the actors reprised their roles from the cartoon, including Frank Welker as Maskutchi. (Tom Kenny, who I suspect played Mimitchi in the cartoon, is notably absent from the game. I'll have to compare both sets of credits sometime.)
Is there a way to find out who voiced which tama? I read somewhere that Frank Welker voiced Maskutchi but I'm not sure about the others.
Here is the voice list:
Charlie Adler, Cam Clarke, Susan Deming, Pat Fraley, David Lewman, Candi Milo, Russi Taylor, Frank W. Welker
Alan Botvinick, Vahag Byurat, Jeanna Crawford, Andrew Hinnebush, Robin Hinnen, Michelle Italiano, Wendy Jacobsmeyer, Tina Lerno, Michael Lynch, Jonathan Pekar, Michael Reed, Jeffrey Steefel, Janice Tanaka