The outside transformation really makes the rest of the basement feel "different"... unfortunately it makes it look and feel smaller because you can't see into the "movie room" anymore.
The transformation on the inside of the room makes that "different" feeling completely worth it! I feel like I have an actual "home theater" now instead of a "movie room" - maybe that doesn't make sense, but before I felt strange calling it a "home theater", now I have no problem at all.
Here is the transformation starting from an old picture of the inside of the room through the current "temporarily done" state. Note that the riser carpet is only temporary until I can decide on and afford new carpet for the whole room.
This was roughly the plan I followed - in this plan the riser is not as wide as the final design, it ended up being 9'6" in the end.
So the remaining to do list for the inside of the room:
1) Tape and mud dywall
2) Paint entire back wall black
3) Put up trim
4) Figure out a solution for the threshold and a way to stop light from leaking under the door
5) Add Deadpool poster to the space between the door and the Kings of Summer poster
6) Decide on and have new carpet installed in the room.
7) Long term - projector and screen.
8) Long term - replace rear row, or at least the corner rear row seat