UPDATE [15/11/10]Just a minor-ish update today.
Added in a few more pokemon that you'll be able to catch in 0.4
I've already shown the bone grave sidequest and Gengar, there will also be...
Oinx: which will be a forced boss battle in the ferreus mines,
Aron: (GASP! gen3) Optional boss in the mines.
Snubull: A kid on route 9 will sell it if you have 5 badges.
Phanpy: Route 10. optional boss.
Poliwag: Must fish in the spot in Route 4 (i've also changed so that totodiles must be fished for too, at imbibo lake though.)
also im currently adding
Pineco: Found at night, at a location im still currently deciding.
Diglett: In the connecting caves.