FT is a pretty basic game, yes? PT had some complicating factors (bug collecting, snapshots of your greenhouse, etc.) that might well make porting more difficult.

We also don't know the licensing issues, either - there may well be issues with artwork or music that make it harder to port some of the later games.

And one thing at a time - start with the easy ports (FT and VV1) to see if there's a demand, then do the harder ones.