diff --git a/Makefile.port b/Makefile.port
index b8ebadb12..747548a78 100644
--- a/Makefile.port
+++ b/Makefile.port
@@ -36,7 +36,7 @@ ROMID ?= ntsc-final
 #
 # Supported values: -O0, -O1, -O2, -O3, -Os, -Og
 
-GCC_OPT_LVL = -Og
+GCC_OPT_LVL = -O0
 
 # ROM_SIZE - The desired ROM size in megabytes.
 #
@@ -86,12 +86,8 @@ endif
 
 # Set whether the target arch is 64- or 32-bit.
 ifneq (,$(findstring 64,$(TARGET_PLATFORM))$(findstring armv8,$(TARGET_PLATFORM)))
-  # TODO: we're not 64-bit compatible yet, error out if building the actual game
-  ifeq (,$(findstring clean,$(MAKECMDGOALS)))
-    $(error 64-bit target platforms are not supported yet)
-  endif
   TARGET_64BIT = 1
-else # TODO
+else
   TARGET_64BIT = 0
 endif
 
@@ -137,6 +133,7 @@ DEFINES := \
   PAL=$(IS_PAL) \
   PIRACYCHECKS=0 \
   ROM_SIZE=$(ROM_SIZE) \
+  PLATFORM_64BIT=1 \
   _LANGUAGE_C=1
 
 ifeq ($(DEBUG),1)
@@ -152,8 +149,12 @@ G_DIR := src/generated/$(ROMID)
 ifneq (,$(findstring windows,$(TARGET_PLATFORM)))
   TARGET_CFLAGS := $(shell pkg-config sdl2 --cflags-only-I)
   TARGET_LDFLAGS := $(shell pkg-config sdl2 --libs) -lz -lopengl32 -static-libstdc++ -ldbghelp
+  ifeq (1,$(TARGET_64BIT))
+    TOOLCHAIN ?= x86_64-w64-mingw32-
+  else
   # on windows/mingw we need this to be built with a 32-bit compiler so it finds the correct libs
-  TOOLCHAIN ?= i686-w64-mingw32-
+    TOOLCHAIN ?= i686-w64-mingw32-
+  endif
 else # assume *nix
   TARGET_CFLAGS := $(shell pkg-config sdl2 --cflags-only-I)
   TARGET_LDFLAGS := $(shell pkg-config sdl2 --libs) -lGL -lz -ldl
diff --git a/include/PR/gbi.h b/include/PR/gbi.h
index d8fd26bf8..e36f15ec2 100644
--- a/include/PR/gbi.h
+++ b/include/PR/gbi.h
@@ -1538,8 +1538,8 @@ typedef struct {
  * Generic Gfx Packet
  */
 typedef struct {
-	unsigned int w0;
-	unsigned int w1;
+	uintptr_t w0;
+	uintptr_t w1;
 } Gwords;
 
 // xxxxxxxx 11223344 44555566 66666777
@@ -1663,7 +1663,7 @@ typedef union {
 {                                                \
     (_SHIFTL((c), 24, 8) | _SHIFTL((p), 16, 8) | \
      _SHIFTL((l), 0, 16)),                       \
-    (unsigned int)(s)                            \
+    (uintptr_t)(s)                            \
 }
 
 #define gDma2p(pkt, c, adrs, len, idx, ofs)                      \
diff --git a/include/PR/os_pi.h b/include/PR/os_pi.h
index 0c7459784..500ec916f 100644
--- a/include/PR/os_pi.h
+++ b/include/PR/os_pi.h
@@ -198,7 +198,7 @@ extern u32 		osPiGetStatus(void);
 extern s32		osPiGetDeviceType(void);
 extern s32		osPiWriteIo(u32, u32);
 extern s32		osPiReadIo(u32, u32 *);
-extern s32		osPiStartDma(OSIoMesg *, s32, s32, u32, void *, u32,
+extern s32		osPiStartDma(OSIoMesg *, s32, s32, uintptr_t, void *, u32,
 				     OSMesgQueue *);
 extern void		osCreatePiManager(OSPri, OSMesgQueue *, OSMesg *, s32);
 
diff --git a/port/src/libultra.c b/port/src/libultra.c
index 74edd9782..708f97bd5 100644
--- a/port/src/libultra.c
+++ b/port/src/libultra.c
@@ -433,7 +433,7 @@ void osInvalDCache(void *a, s32 b)
 
 }
 
-s32 osPiStartDma(OSIoMesg *mb, s32 priority, s32 direction, uintptr_t devAddr, void *vAddr, size_t nbytes, OSMesgQueue *mq)
+s32 osPiStartDma(OSIoMesg *mb, s32 priority, s32 direction, uintptr_t devAddr, void *vAddr, u32 nbytes, OSMesgQueue *mq)
 {
 	memcpy(vAddr, (const void *)devAddr, nbytes);
 	return 0;
diff --git a/port/src/main.c b/port/src/main.c
index 10150f7ae..f9af8ac1e 100644
--- a/port/src/main.c
+++ b/port/src/main.c
@@ -129,6 +129,7 @@ int main(int argc, const char **argv)
 	sysLogPrintf(LOG_NOTE, "rom  file at %p - %p", g_RomFile, g_RomFile + g_RomFileSize);
 
 	g_SndDisabled = sysArgCheck("--no-sound");
+	g_SndDisabled = true;
 
 	g_StageNum = sysArgGetInt("--boot-stage", STAGE_TITLE);
 
diff --git a/src/include/gunscript.h b/src/include/gunscript.h
index 224c1dd7c..b3cd21870 100644
--- a/src/include/gunscript.h
+++ b/src/include/gunscript.h
@@ -17,10 +17,10 @@
 	{ GUNCMD_PLAYSOUND, 0, keyframe, sound },
 
 #define gunscript_include(unk1, address) \
-	{ GUNCMD_INCLUDE, unk1, 0, (u32)address },
+	{ GUNCMD_INCLUDE, unk1, 0, (uintptr_t)address },
 
 #define gunscript_random(probability, address) \
-	{ GUNCMD_RANDOM, 0, probability, (u32)address },
+	{ GUNCMD_RANDOM, 0, probability, (uintptr_t)address },
 
 #define gunscript_repeatuntilfull(triggerkey, dontloop, gototrigger) \
 	{ GUNCMD_REPEATUNTILFULL, 0, triggerkey, (dontloop << 16) | gototrigger },
diff --git a/src/include/platform.h b/src/include/platform.h
index 30615f750..949ff31a6 100644
--- a/src/include/platform.h
+++ b/src/include/platform.h
@@ -29,11 +29,6 @@
 	#error "Unknown CPU arch."
 #endif
 
-// TODO: remove this after 64-bit support is in place
-#ifdef PLATFORM_64BIT
-	#error "64-bit platforms are currently not supported."
-#endif
-
 // detect endianness
 #if defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__)
 	#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
diff --git a/src/include/types.h b/src/include/types.h
index 2a0491896..41ec678d3 100644
--- a/src/include/types.h
+++ b/src/include/types.h
@@ -5357,7 +5357,7 @@ struct guncmd {
 	u8 type;
 	u8 unk01;
 	u16 unk02;
-	s32 unk04;
+	uintptr_t unk04;
 };
 
 struct pakthing {
diff --git a/src/lib/ultra/io/pidma.c b/src/lib/ultra/io/pidma.c
index 75d758d1b..1fc7b61d7 100644
--- a/src/lib/ultra/io/pidma.c
+++ b/src/lib/ultra/io/pidma.c
@@ -1,7 +1,7 @@
 #include <os_internal.h>
 #include "piint.h"
 
-s32 osPiStartDma(OSIoMesg *mb, s32 priority, s32 direction, u32 devAddr, void *dramAddr, u32 size, OSMesgQueue *mq)
+s32 osPiStartDma(OSIoMesg *mb, s32 priority, s32 direction, uintptr_t devAddr, void *dramAddr, u32 size, OSMesgQueue *mq)
 {
 	register s32 ret;