This post relies on familiarity with the gameplay / affordances in Thief. You may want to read Dark Past or my write-up on "Assassins." You're also encouraged to read through Mr. Monahan's Design Reboot blog.
I've been watching Thief 4 coverage
over the past months and I'm increasingly convinced that I'm going to hate it. So let's pretend, just for fun, that I'm making a Thief-like... What are the best qualities of Thief to preserve, and which parts of the sacred cow would I lop-off? Here's what I'm thinking:
KEEP: Level size.
Thief levels vary from medium to extremely large. "Life of the Party" was a single mission where you had to traverse an entire cityscape of rooftops through two dozen buildings and then also infiltrate a huge skyscraper at the end. Sheer architectural scale is important to maintain a sense of...
KEEP: Infiltration and exfiltration.
You have to get in, rob the place, and get out. There's always an outside and an inside, and it's great to feel that you're not supposed to be inside. But previous Thief games usually neglected exfiltration as redundant backtracking or worse -- something totally nonexistent because you've already incapacitated the entire guard garrison by the end of a mission. (My favorite Thief 1 mission, Assassins, is one of the few missions to really do something with exfiltration.)
ADD: Organic use of dynamic lighting.
With dynamic lighting and shadows, you can do totally unimaginative setpieces where you have to hide in a guard's shadow or hide in the shadow of moving objects on a conveyor belt. But something else is going on here: with dynamic lighting, open doors and windows become light sources
-- and if you can close the door or block the window, you've "extinguished" that light -- but if there's a ramp in front of that window, you can't put anything there to block it because it'll just slide down, etc. That possibility sounds much less horrible than a contrived puzzle that you designed to death.