Iterate on the original game as much as you like!
Don't like the idea of "shooting"?
Want to change the
theme around in a big way?
Here are some examples of games with unique takes on the
Wolfenstein 3D formula:
H.U.R.L.
(1995)
▶ Click to Play!
Nitemare 3D
(1994)
▶ Click to Play!
Super 3D Noah's Ark
(1995)
▶ Click to Play!
Chex Quest
(1996)
▶ Click to Play!
To make your entry more Wolfenstein-like,
consider
featuring at least some of the following aspects:
First-Person
You are the camera, with only a "weapon" (or other held
object) to represent the player moving through space.
Optionally, an increasingly-damaged portrait of the
character is featured in the UI.
Flat Level Design
There are no stairs or ramps. Every floor and ceiling in
the game is at the same height. Every wall is a straight
edge; instead of diagonal walls or curved hallways, there
are only zig-zags.
Flat Aesthetic
Flat, 2D NPC's and items occupy a 3D space, and always
face the camera (billboarding). Textures are pixelated and
lack true dimension.
Ground Items
Door keys, health pickups, treasure, and ammo litter the
ground, all awaiting collection by the player. There are
only 4 weapons in the game!
Secret Areas
Spamming the activate key on various walls sometimes
reveals a hidden room with secret exits, items, or
enemies.
Again, you should keep or tweak as much of this as you
like.
But I thought you should know the reference point we're
starting from!