Restore Hidden Palace pulsing orb

(Original guide by lavagaming1)

Files You Need Before Starting

Before you start, download this file and place it your disassembly. Media:HPZ.rar

Preview

Hidden Palace Zone was removed from the final (and pre-release builds) of Sonic the Hedgehog 2 however some of Hidden Palace object items are still present within the game code.

Restoring The Green Orbs

To restore the pulsing orbs, go to your S2.asm and search for object 71. You will find this code.

; ===========================================================================
; ----------------------------------------------------------------------------
; Object 71 - Bridge stake and pulsing orb from Hidden Palace Zone
; ----------------------------------------------------------------------------
; Sprite_112F0:
Obj71:
	moveq	#0,d0
	move.b	routine(a0),d0
	move.w	Obj71_Index(pc,d0.w),d1
	jmp	Obj71_Index(pc,d1.w)
; ===========================================================================
; off_112FE:
Obj71_Index:	offsetTable
		offsetTableEntry.w Obj71_Init	; 0
		offsetTableEntry.w Obj71_Main	; 2
; ---------------------------------------------------------------------------
; dword_11302:
Obj71_InitData:
	objsubdecl 3, Obj11_MapUnc_FC28,  make_art_tile(ArtTile_ArtNem_HPZ_Bridge,3,0), 4, 1		; Hidden Palace bridge
	objsubdecl 0, Obj71_MapUnc_11396, make_art_tile(ArtTile_ArtNem_HPZOrb,3,1), $10, 1		; Hidden Palace pulsing orb
	objsubdecl 0, Obj71_MapUnc_11576, make_art_tile(ArtTile_ArtNem_MtzLavaBubble,2,0), $10, 1	; MTZ lava bubble
; ===========================================================================
; loc_1131A:
Obj71_Init:
	addq.b	#2,routine(a0)
	move.b	subtype(a0),d0
	andi.w	#$F,d0
	lsl.w	#3,d0
	lea	Obj71_InitData(pc),a1
	lea	(a1,d0.w),a1
	move.b	(a1),mapping_frame(a0)
	move.l	(a1)+,mappings(a0)
	move.w	(a1)+,art_tile(a0)
	bsr.w	Adjust2PArtPointer
	ori.b	#4,render_flags(a0)
	move.b	(a1)+,width_pixels(a0)
	move.b	(a1)+,priority(a0)
	move.b	subtype(a0),d0
	andi.w	#$F0,d0
	lsr.b	#4,d0
	move.b	d0,anim(a0)
; loc_1135C:
Obj71_Main:
	lea	(Ani_obj71).l,a1
	bsr.w	AnimateSprite
	bra.w	MarkObjGone
; ===========================================================================
; off_1136A:
Ani_obj71:	offsetTable
		offsetTableEntry.w byte_11372	; 0
		offsetTableEntry.w byte_1137A	; 1
		offsetTableEntry.w byte_11389	; 2
		offsetTableEntry.w byte_11392	; 3
byte_11372:	dc.b   8,  3,  3,  4,  5,  5,  4,$FF
	rev02even
byte_1137A:	dc.b   5,  0,  0,  0,  1,  2,  3,  3,  2,  1,  2,  3,  3,  1,$FF
	rev02even
byte_11389:	dc.b  $B,  0,  1,  2,  3,  4,  5,$FD,  3
	rev02even
byte_11392:	dc.b $7F,  6,$FD,  2
	even

; --------------------------------------------------------------------------------
; sprite mappings
; --------------------------------------------------------------------------------
Obj71_MapUnc_11396:	BINCLUDE "mappings/sprite/obj71_a.bin"
; ----------------------------------------------------------------------------------------
; Unknown sprite mappings
; ----------------------------------------------------------------------------------------
Obj1C_MapUnc_113D6:	BINCLUDE "mappings/sprite/obj1C_a.bin"
; --------------------------------------------------------------------------------
; Unknown sprite mappings
; --------------------------------------------------------------------------------
Obj1C_MapUnc_113EE:	BINCLUDE "mappings/sprite/obj1C_b.bin"
; -------------------------------------------------------------------------------
; sprite mappings
; -------------------------------------------------------------------------------
Obj1C_MapUnc_11406:	BINCLUDE "mappings/sprite/obj1C_c.bin"
; --------------------------------------------------------------------------------
; sprite mappings
; --------------------------------------------------------------------------------
Obj1C_MapUnc_114AE:	BINCLUDE "mappings/sprite/obj1C_d.bin"
; --------------------------------------------------------------------------------
; sprite mappings
; --------------------------------------------------------------------------------
Obj1C_MapUnc_11552:	BINCLUDE "mappings/sprite/obj1C_e.bin"
; ----------------------------------------------------------------------------
; sprite mappings
; ----------------------------------------------------------------------------
Obj71_MapUnc_11576:	BINCLUDE "mappings/sprite/obj71_b.bin"
; ===========================================================================

    if gameRevision<2
	nop
    endif

copy this line ArtNem_HPZ_Bridge search for this code

 
;---------------------------------------------------------------------------------------
; Nemesis compressed art (16 blocks)
; Button			ArtNem_78DAC:
	even
ArtNem_Button:	           BINCLUDE	"art/nemesis/Button.bin"

and paste below it this line  

        even
ArtNem_HPZOrb:             BINCLUDE       "HPZ/Orbs.bin"
         even

Now making the game load the art

in sonic 2 final hidden palace uses the same PlrList as oil ocean if you dont know what is the(PlrList) its basically what tells the game what object that it has to load for each zone so if you didnt make a PlrList for hidden palace just use oil ocean PlrList paste this line in oil ocean PlrList

plreq ArtTile_ArtNem_HPZOrb,ArtNem_HPZOrb

now you should have the pulsing orb working in hidden palace

the results

and there you have it happy hacking