Sounds like he is saying to me.
Know nothing about the game but that is what my Japanese ear picks up.
EDIT: Just found this:
> ****
RE-EDIT: Found these, too.
Go to paragraph (about) #9, which starts with "It's a shame":
> It’s a shame, then, that the in-game voices are a bit grating. The voice actors themselves aren’t the problem, just one particular usage of them- i.e. the way Driller-san and friends say **‘Lucky!’** (or in the case of the dog, ‘Lucky-wan!’) every time you pick up an oxygen capsule.
Read the paragraph (about #5) stating with "Graphically":
> ... the repeated sound clip of **‘’lucky!’’** when you collect an air tank ...
I have nothing more to say, really.