Personally I think it should be up to the person making the game what size the textures are. You should make them at least 512 square and let the programmer scale them to the size they require.
Also you should be careful with the lighting. I see lots of top left shadows being cast. Generally you should only add shadows from the top unless you have a light source on the texture. Otherwise the texture looks wrong once combined with lightmaps.
Also you should be careful with the lighting. I see lots of top left shadows being cast. Generally you should only add shadows from the top unless you have a light source on the texture. Otherwise the texture looks wrong once combined with lightmaps.