Alternate "original" themes that are less faithful to the original
game.

Episode		Original theme		Theme here
E1		town			egypt
E2		egypt			egypt
E3		castle			town
E4		egypt			egypt
E5		castle			castle
E6		town			town

Note that E2 really needs its own “lava” theme, but Egypt is as close
as we get with the three themes the code currently has.

diff -ur Oblige-7.70-bright/games/heretic/levels.lua Oblige-7.70-ObHack/games/heretic/levels.lua
--- Oblige-7.70-bright/games/heretic/levels.lua	2026-07-18 23:12:14.584466500 -0600
+++ Oblige-7.70-ObHack/games/heretic/levels.lua	2026-08-10 21:13:38.340220100 -0600
@@ -28,7 +28,7 @@
   {
     ep_index = 1
 
-    theme = "castle"
+    theme = "egypt"
     boss = "Ironlich"
     sky_light = 0.95
   }
@@ -37,7 +37,7 @@
   {
     ep_index = 2
 
-    theme = "castle"
+    theme = "egypt"
     boss = "Maulotaur"
     sky_light = 0.95
   }
@@ -46,7 +46,7 @@
   {
     ep_index = 3
 
-    theme = "castle"
+    theme = "town"
     boss = "D_sparil"
     sky_light = 0.95
   }
@@ -55,7 +55,7 @@
   {
     ep_index = 4
 
-    theme = "castle"
+    theme = "egypt"
     boss = "Ironlich"
     sky_light = 0.95
   }
@@ -83,7 +83,7 @@
   {
     ep_index = 6
 
-    theme = "castle"
+    theme = "town"
     boss = "Ironlich"
     sky_light = 0.70
   }