diff --git a/include/functions.h b/include/functions.h
index 212e03cf49..6be2d14322 100644
--- a/include/functions.h
+++ b/include/functions.h
@@ -1210,7 +1210,7 @@ void Player_DrawGetItem(GlobalContext* globalCtx, Player* player);
 u32 func_80091738(GlobalContext* globalCtx, u8* segment, SkelAnime* skelAnime);
 void func_8009214C(GlobalContext* globalCtx, u8* segment, struct_80091A24_arg3* arg2, Vec3f* pos, Vec3s* rot, f32 scale,
                    s32 sword, s32 tunic, s32 shield, s32 boots);
-void PreNMI_Init(PreNMIContext* prenmiCtx);
+void PreNMI_Init(GameState* thisx);
 Vec3f* Quake_AddVec(Vec3f* dst, Vec3f* arg1, VecSph* arg2);
 void Quake_UpdateShakeInfo(QuakeRequest* req, ShakeInfo* shake, f32 y, f32 x);
 s16 Quake_Callback1(QuakeRequest* req, ShakeInfo* shake);
@@ -1282,8 +1282,8 @@ s32 func_8009728C(GlobalContext* globalCtx, RoomContext* roomCtx, s32 roomNum);
 s32 func_800973FC(GlobalContext* globalCtx, RoomContext* roomCtx);
 void Room_Draw(GlobalContext* globalCtx, Room* room, u32 flags);
 void func_80097534(GlobalContext* globalCtx, RoomContext* roomCtx);
-void Sample_Destroy(SampleContext* this);
-void Sample_Init(SampleContext* this);
+void Sample_Destroy(GameState* thisx);
+void Sample_Init(GameState* thisx);
 void Inventory_ChangeEquipment(s16 equipment, u16 value);
 u8 Inventory_DeleteEquipment(GlobalContext* globalCtx, s16 equipment);
 void Inventory_ChangeUpgrade(s16 upgrade, s16 value);
@@ -1583,9 +1583,9 @@ s32 func_800BC56C(GlobalContext* globalCtx, s16 arg1);
 void func_800BC590(GlobalContext* globalCtx);
 void func_800BC5E0(GlobalContext* globalCtx, s32 arg1);
 Gfx* func_800BC8A0(GlobalContext* globalCtx, Gfx* gfx);
-void Gameplay_Destroy(GlobalContext* globalCtx);
-void Gameplay_Init(GlobalContext* globalCtx);
-void Gameplay_Main(GlobalContext* globalCtx);
+void Gameplay_Destroy(GameState* thisx);
+void Gameplay_Init(GameState* thisx);
+void Gameplay_Main(GameState* thisx);
 s32 Gameplay_InCsMode(GlobalContext* globalCtx);
 f32 func_800BFCB8(GlobalContext* globalCtx, MtxF* mf, Vec3f* vec);
 void* Gameplay_LoadFile(GlobalContext* globalCtx, RomFile* file);
@@ -2626,14 +2626,14 @@ void func_801109B0(GlobalContext* globalCtx);
 void func_80110F68(GlobalContext* globalCtx);
 void func_80112098(GlobalContext* globalCtx);
 
-void Title_Init(TitleContext*);
-void Title_Destroy(TitleContext* this);
-void Select_Init(SelectContext*);
-void Select_Destroy(SelectContext*);
-void Opening_Init(OpeningContext* this);
-void Opening_Destroy(OpeningContext* this);
-void func_80811A20(GameState*); // FileChoose_Init
-void func_80811A18(GameState*); // FileChoose_Destroy
+void Title_Init(GameState* thisx);
+void Title_Destroy(GameState* thisx);
+void Select_Init(GameState* thisx);
+void Select_Destroy(GameState* thisx);
+void Opening_Init(GameState* thisx);
+void Opening_Destroy(GameState* thisx);
+void func_80811A20(GameState* thisx); // FileChoose_Init
+void func_80811A18(GameState* thisx); // FileChoose_Destroy
 
 void func_80823994(PauseContext*, f32, f32, f32);
 void func_800949A8(GraphicsContext*);
diff --git a/src/code/z_play.c b/src/code/z_play.c
index 3700054563..bbb77f7da3 100644
--- a/src/code/z_play.c
+++ b/src/code/z_play.c
@@ -146,8 +146,8 @@ Gfx* func_800BC8A0(GlobalContext* globalCtx, Gfx* gfx) {
                 globalCtx->lightCtx.unk_0A, 1000);
 }
 
-void Gameplay_Destroy(GlobalContext* globalCtx) {
-    s32 pad;
+void Gameplay_Destroy(GameState* thisx) {
+    GlobalContext* globalCtx = (GlobalContext*)thisx;
     Player* player = PLAYER;
 
     globalCtx->state.gfxCtx->callback = NULL;
@@ -191,7 +191,8 @@ void Gameplay_Destroy(GlobalContext* globalCtx) {
 #ifdef NON_MATCHING
 // regalloc and stack usage differences
 // also missing some extra duplicated instructions
-void Gameplay_Init(GlobalContext* globalCtx) {
+void Gameplay_Init(GameState* thisx) {
+    GlobalContext* globalCtx = (GlobalContext*)thisx;
     GraphicsContext* gfxCtx;
     void* zAlloc; // 0x84
     void* zAllocAligned;
@@ -1329,7 +1330,9 @@ void Gameplay_Draw(GlobalContext* globalCtx) {
 #pragma GLOBAL_ASM("asm/non_matchings/code/z_play/Gameplay_Draw.s")
 #endif
 
-void Gameplay_Main(GlobalContext* globalCtx) {
+void Gameplay_Main(GameState* thisx) {
+    GlobalContext* globalCtx = (GlobalContext*)thisx;
+    
     D_8012D1F8 = &globalCtx->state.input[0];
 
     DebugDisplay_Init();
diff --git a/src/code/z_prenmi.c b/src/code/z_prenmi.c
index 678e393b09..8de5bd2135 100644
--- a/src/code/z_prenmi.c
+++ b/src/code/z_prenmi.c
@@ -1,30 +1,30 @@
 #include "global.h"
 #include "vt.h"
 
-void func_80092320(PreNMIContext* prenmiCtx) {
-    prenmiCtx->state.running = false;
-    prenmiCtx->state.init = NULL;
-    prenmiCtx->state.size = 0;
+void func_80092320(PreNMIContext* this) {
+    this->state.running = false;
+    this->state.init = NULL;
+    this->state.size = 0;
 }
 
-void PreNMI_Update(PreNMIContext* prenmiCtx) {
+void PreNMI_Update(PreNMIContext* this) {
     osSyncPrintf(VT_COL(YELLOW, BLACK) "prenmi_move\n" VT_RST);
 
     // Strings existing only in rodata
     ("../z_prenmi.c");
     ("(int)volume = %d\n");
 
-    if (prenmiCtx->timer == 0) {
+    if (this->timer == 0) {
         ViConfig_UpdateVi(1);
-        func_80092320(prenmiCtx);
+        func_80092320(this);
         return;
     }
 
-    prenmiCtx->timer--;
+    this->timer--;
 }
 
-void PreNMI_Draw(PreNMIContext* prenmiCtx) {
-    GraphicsContext* gfxCtx = prenmiCtx->state.gfxCtx;
+void PreNMI_Draw(PreNMIContext* this) {
+    GraphicsContext* gfxCtx = this->state.gfxCtx;
 
     osSyncPrintf(VT_COL(YELLOW, BLACK) "prenmi_draw\n" VT_RST);
 
@@ -34,26 +34,30 @@ void PreNMI_Draw(PreNMIContext* prenmiCtx) {
     func_80095248(gfxCtx, 0, 0, 0);
     func_800940B0(gfxCtx);
     gDPSetFillColor(oGfxCtx->polyOpa.p++, (GPACK_RGBA5551(255, 255, 255, 1) << 16) | GPACK_RGBA5551(255, 255, 255, 1));
-    gDPFillRectangle(oGfxCtx->polyOpa.p++, 0, prenmiCtx->timer + 100, SCREEN_WIDTH - 1, prenmiCtx->timer + 100);
+    gDPFillRectangle(oGfxCtx->polyOpa.p++, 0, this->timer + 100, SCREEN_WIDTH - 1, this->timer + 100);
 
     CLOSE_DISPS(gfxCtx, "../z_prenmi.c", 112);
 }
 
-void PreNMI_Main(PreNMIContext* prenmiCtx) {
-    PreNMI_Update(prenmiCtx);
-    PreNMI_Draw(prenmiCtx);
+void PreNMI_Main(GameState* thisx) {
+    PreNMIContext* this = (PreNMIContext*)thisx;
+    
+    PreNMI_Update(this);
+    PreNMI_Draw(this);
 
-    prenmiCtx->state.unk_A0 = 1;
+    this->state.unk_A0 = 1;
 }
 
-void PreNMI_Destroy(PreNMIContext* prenmiCtx) {
+void PreNMI_Destroy(GameState* thisx) {
 }
 
-void PreNMI_Init(PreNMIContext* prenmiCtx) {
-    prenmiCtx->state.main = PreNMI_Main;
-    prenmiCtx->state.destroy = PreNMI_Destroy;
-    prenmiCtx->timer = 30;
-    prenmiCtx->unk_A8 = 10;
+void PreNMI_Init(GameState* thisx) {
+    PreNMIContext* this = (PreNMIContext*)thisx;
+
+    this->state.main = PreNMI_Main;
+    this->state.destroy = PreNMI_Destroy;
+    this->timer = 30;
+    this->unk_A8 = 10;
 
     R_UPDATE_RATE = 1;
 }
diff --git a/src/code/z_sample.c b/src/code/z_sample.c
index d5383b3732..7df8854395 100644
--- a/src/code/z_sample.c
+++ b/src/code/z_sample.c
@@ -38,12 +38,14 @@ void Sample_Draw(SampleContext* this) {
     CLOSE_DISPS(gfxCtx, "../z_sample.c", 111);
 }
 
-void Sample_Main(SampleContext* this) {
+void Sample_Main(GameState* thisx) {
+    SampleContext* this = (SampleContext*)thisx;
+
     Sample_Draw(this);
     Sample_HandleStateChange(this);
 }
 
-void Sample_Destroy(SampleContext* this) {
+void Sample_Destroy(GameState* thisx) {
 }
 
 void Sample_SetupView(SampleContext* this) {
@@ -83,7 +85,9 @@ void Sample_LoadTitleStatic(SampleContext* this) {
     DmaMgr_SendRequest1(this->staticSegment, _title_staticSegmentRomStart, size, "../z_sample.c", 164);
 }
 
-void Sample_Init(SampleContext* this) {
+void Sample_Init(GameState* thisx) {
+    SampleContext* this = (SampleContext*)thisx;
+    
     this->state.main = Sample_Main;
     this->state.destroy = Sample_Destroy;
     R_UPDATE_RATE = 1;
diff --git a/src/overlays/gamestates/ovl_opening/z_opening.c b/src/overlays/gamestates/ovl_opening/z_opening.c
index 9fe700d050..9c29d880b7 100644
--- a/src/overlays/gamestates/ovl_opening/z_opening.c
+++ b/src/overlays/gamestates/ovl_opening/z_opening.c
@@ -19,16 +19,20 @@ void Opening_SetupTitleScreen(OpeningContext* this) {
 void func_80803C5C(OpeningContext* this) {
 }
 
-void Opening_Main(OpeningContext* this) {
+void Opening_Main(GameState* thisx) {
+    OpeningContext* this = (OpeningContext*)thisx;
+
     func_80095248(this->state.gfxCtx, 0, 0, 0);
     Opening_SetupTitleScreen(this);
     func_80803C5C(this);
 }
 
-void Opening_Destroy(OpeningContext* this) {
+void Opening_Destroy(GameState* thisx) {
 }
 
-void Opening_Init(OpeningContext* this) {
+void Opening_Init(GameState* thisx) {
+    OpeningContext* this = (OpeningContext*)thisx;
+    
     R_UPDATE_RATE = 1;
     Matrix_Init(&this->state);
     View_Init(&this->view, this->state.gfxCtx);
diff --git a/src/overlays/gamestates/ovl_select/z_select.c b/src/overlays/gamestates/ovl_select/z_select.c
index f858abf0fd..2a7d03d4f3 100644
--- a/src/overlays/gamestates/ovl_select/z_select.c
+++ b/src/overlays/gamestates/ovl_select/z_select.c
@@ -566,20 +566,23 @@ void Select_Draw(SelectContext* this) {
     CLOSE_DISPS(gfxCtx, "../z_select.c", 1037);
 }
 
-void Select_Main(SelectContext* this) {
+void Select_Main(GameState* thisx) {
+    SelectContext* this = (SelectContext*)thisx;
+    
     Select_UpdateMenu(this);
     Select_Draw(this);
 }
 
-void Select_Destroy(SelectContext* this) {
+void Select_Destroy(GameState* thisx) {
     osSyncPrintf("%c", 7);
     // "view_cleanup will hang, so it won't be called"
     osSyncPrintf("*** view_cleanupはハングアップするので、呼ばない ***\n");
 }
 
-void Select_Init(SelectContext* this) {
+void Select_Init(GameState* thisx) {
+    SelectContext* this = (SelectContext*)thisx;
     u32 size;
-    s32 pad[2];
+    s32 pad;
 
     this->state.main = Select_Main;
     this->state.destroy = Select_Destroy;
diff --git a/src/overlays/gamestates/ovl_title/z_title.c b/src/overlays/gamestates/ovl_title/z_title.c
index 72ce3e69a4..0db9dbde50 100644
--- a/src/overlays/gamestates/ovl_title/z_title.c
+++ b/src/overlays/gamestates/ovl_title/z_title.c
@@ -124,8 +124,8 @@ void Title_Draw(TitleContext* this) {
     CLOSE_DISPS(this->state.gfxCtx, "../z_title.c", 483);
 }
 
-void Title_Main(TitleContext* this) {
-    s32 pad;
+void Title_Main(GameState* thisx) {
+    TitleContext* this = (TitleContext*)thisx;
 
     OPEN_DISPS(this->state.gfxCtx, "../z_title.c", 494);
 
@@ -154,13 +154,15 @@ void Title_Main(TitleContext* this) {
     CLOSE_DISPS(this->state.gfxCtx, "../z_title.c", 541);
 }
 
-void Title_Destroy(TitleContext* this) {
+void Title_Destroy(GameState* thisx) {
+    TitleContext* this = (TitleContext*)thisx;
+
     Sram_InitSram(this, &this->sramCtx);
 }
 
-void Title_Init(TitleContext* this) {
+void Title_Init(GameState* thisx) {
     u32 size = (u32)_nintendo_rogo_staticSegmentRomEnd - (u32)_nintendo_rogo_staticSegmentRomStart;
-    s32 pad;
+    TitleContext* this = (TitleContext*)thisx;
 
     this->staticSegment = GameState_Alloc(&this->state, size, "../z_title.c", 611);
     osSyncPrintf("z_title.c\n");