Not too much of a problem to redraw graphics - the main work so far has been on the tiles and level design -
In terms of plot - there isn't any significant changes to be made - the aim was to catch the baddie - rescue a prisoner and most of the problems and solutions will still work ok.
Also, after the Danger Mouse game, I was thinking of doing a sort of update of an old BBC arcade adventure game called Thunderstruck - so this sort of makes it easier to move onto the larger game next.
In terms of the working title I was thinking
"Dylan the Space Man versus the Green Smelly Alien From Mars" aka "Dylan the Space Man versus the Green Smelly Alien From Mars who has a striking resemblance to a toad but is no way based on any TV evil masterminds from children's cartoon series of the 1980s".
At least it might give the game the longest title entry in the Hall of Light database.
The Danger Mouse tile set will still exist - so a simple changing of the graphics file would make it all DM themed - but perhaps that will remain a private copy or the sprite file could be loaded up so individuals who want to make it DM themed can do.