we are currently adding room sizes and making levels/rooms for all the new enemies and content. 90% of the new enemies are added, 50% of the new bosses, 95% of the new items and about 75% of the level art is done.
large chunk wise we still need to do all the games cut scenes and menus, playable characters, sound effects and implement all the game secrets/unlocks.
once all that is done we should be spending a month or so polishing and play testing.
i like to design on the fly, and design around new additions as we add them. we are currently working on co-op and i came up with a few really neat designs for it that id like to implement but will take an extra few days to do.. so its hard to say how much is left. but its getting there.
i hope to show near final screen shots in the next few weeks with almost all the visual effects and details added.