>> but I'm going to be bogged down my disk access:

Hmm, I'd be interested to see how DBM::Deep plays with open's mmap option (as of yet untested/unbenchmarked):

open(DATA, '<+:mmap', 'game.dbm')
my $db = DBM::Deep->new( { fh => \*DATA } );
[download]

Update: Have benchmarked. No appreciable benefits with the above :-|

Now looking at the storage => ... option.