diff --git a/Makefile.mak b/Makefile.mak
index d166323e..84c55af3 100644
--- a/Makefile.mak
+++ b/Makefile.mak
@@ -126,7 +126,7 @@ bin\th04\op.exe: bin\th04\op.obj th04\m_char.cpp bin\th01\vplanset.obj bin\th02\
 $**
 |
 
-bin\th04\main.exe: bin\th04\main.obj bin\th04\slowdown.obj th04\demo.cpp th04\ems.cpp th04\playfld.cpp th04\f_dialog.cpp th04\dialog.cpp bin\th04\player_p.obj bin\th04\scoreupd.obj th04\hud_ovrl.cpp bin\th04\cfg_lres.obj bin\th04\mb_inv.obj bin\th04\boss_bd.obj bin\th01\vplanset.obj bin\th03\vector2.obj bin\th02\frmdely1.obj bin\th03\hfliplut.obj th04\mpn_free.cpp bin\th04\input_w.obj th04\mpn_l_i.cpp bin\th04\vector.obj bin\th04\snd_pmdr.obj bin\th04\snd_mmdr.obj bin\th04\snd_kaja.obj bin\th04\snd_mode.obj bin\th04\snd_load.obj bin\th04\cdg_put.obj bin\th04\exit.obj bin\th04\initmain.obj bin\th04\cdg_p_na.obj bin\th04\cdg_p_pr.obj bin\th04\input_s.obj bin\th04\snd_se_r.obj bin\th04\snd_se.obj bin\th04\cdg_load.obj th04\gather.cpp bin\th04\scrolly3.obj bin\th04\motion_3.obj th04\midboss.cpp bin\th04\hud_hp.obj th04\mb_dft.cpp bin\th04\vector2n.obj bin\th04\spark_a.obj bin\th04\grcg_3.obj bin\th04\it_spl_u.obj th04\boss_4m.cpp th04\bullet_u.cpp th04\bullet_a.cpp th04\boss.cpp th04\boss_4r.cpp th04\boss_x2.cpp
+bin\th04\main.exe: bin\th04\main.obj bin\th04\slowdown.obj th04\demo.cpp th04\ems.cpp th04\playfld.cpp th04\f_dialog.cpp th04\dialog.cpp th04\player_m.cpp bin\th04\player_p.obj bin\th04\scoreupd.obj th04\hud_ovrl.cpp bin\th04\cfg_lres.obj bin\th04\mb_inv.obj bin\th04\boss_bd.obj bin\th01\vplanset.obj bin\th03\vector2.obj bin\th02\frmdely1.obj bin\th03\hfliplut.obj th04\mpn_free.cpp bin\th04\input_w.obj th04\mpn_l_i.cpp bin\th04\vector.obj bin\th04\snd_pmdr.obj bin\th04\snd_mmdr.obj bin\th04\snd_kaja.obj bin\th04\snd_mode.obj bin\th04\snd_load.obj bin\th04\cdg_put.obj bin\th04\exit.obj bin\th04\initmain.obj bin\th04\cdg_p_na.obj bin\th04\cdg_p_pr.obj bin\th04\input_s.obj bin\th04\snd_se_r.obj bin\th04\snd_se.obj bin\th04\cdg_load.obj th04\gather.cpp bin\th04\scrolly3.obj bin\th04\motion_3.obj th04\midboss.cpp bin\th04\hud_hp.obj th04\mb_dft.cpp bin\th04\vector2n.obj bin\th04\spark_a.obj bin\th04\grcg_3.obj bin\th04\it_spl_u.obj th04\boss_4m.cpp th04\bullet_u.cpp th04\bullet_a.cpp th04\boss.cpp th04\boss_4r.cpp th04\boss_x2.cpp
 	$(CC) $(CFLAGS) $(LARGE_LFLAGS) -DGAME=4 -DBINARY='M' -3 -Z -nbin\th04\ -eMAIN.EXE @&&|
 $**
 |
diff --git a/th04/main/player/move.asm b/th04/main/player/move.asm
deleted file mode 100644
index 6014066e..00000000
--- a/th04/main/player/move.asm
+++ /dev/null
@@ -1,117 +0,0 @@
-; move_ret_t pascal near player_move(int input);
-public PLAYER_MOVE
-player_move	proc near
-@@input_local	= word ptr -2
-@@input      	= word ptr  4
-
-	enter	2, 0
-	mov	dl, MOVE_VALID
-	mov	ax, [bp+@@input]
-	mov	[bp+@@input_local], ax
-	mov	cx, @@num_cases
-	mov	bx, offset @@switch_table
-
-@@case_lookup:
-	mov	ax, cs:[bx]
-	cmp	ax, [bp+@@input_local]
-	jz	short @@switch
-	add	bx, 2
-	loop	@@case_lookup
-	jmp	short @@default
-; ---------------------------------------------------------------------------
-
-@@switch:
-	jmp	word ptr cs:[bx+@@case_to_target] ; switch jump
-
-@@standing_still:
-	mov	dl, MOVE_NOINPUT
-	jmp	short @@ret
-; ---------------------------------------------------------------------------
-
-@@left:
-	mov	_player_pos.velocity.x, -playchar_speed_aligned
-	jmp	short @@ret
-; ---------------------------------------------------------------------------
-
-@@down_left:
-	mov	_player_pos.velocity.x, -playchar_speed_diagonal
-	mov	_player_pos.velocity.y, playchar_speed_diagonal
-	jmp	short @@ret
-; ---------------------------------------------------------------------------
-
-@@down:
-	mov	_player_pos.velocity.y, playchar_speed_aligned
-	jmp	short @@ret
-; ---------------------------------------------------------------------------
-
-@@down_right:
-	mov	_player_pos.velocity.x, playchar_speed_diagonal
-	mov	_player_pos.velocity.y, playchar_speed_diagonal
-	jmp	short @@ret
-; ---------------------------------------------------------------------------
-
-@@right:
-	mov	_player_pos.velocity.x, playchar_speed_aligned
-	jmp	short @@ret
-; ---------------------------------------------------------------------------
-
-@@up_right:
-	mov	_player_pos.velocity.x, playchar_speed_diagonal
-	jmp	short @@up_left_y
-; ---------------------------------------------------------------------------
-
-@@up:
-	mov	_player_pos.velocity.y, -playchar_speed_aligned
-	jmp	short @@ret
-; ---------------------------------------------------------------------------
-
-@@up_left:
-	mov	_player_pos.velocity.x, -playchar_speed_diagonal
-
-@@up_left_y:
-	mov	_player_pos.velocity.y, -playchar_speed_diagonal
-	jmp	short @@ret
-; ---------------------------------------------------------------------------
-
-@@default:
-	mov	dl, MOVE_INVALID
-
-@@ret:
-	mov	al, dl
-	leave
-	retn	2
-
-; ---------------------------------------------------------------------------
-	db    0
-@@switch_table	label word
-	; value table for switch statement
-	dw	INPUT_NONE
-	dw	INPUT_UP
-	dw	INPUT_DOWN
-	dw	INPUT_LEFT
-	dw	INPUT_UP or INPUT_LEFT
-	dw 	INPUT_DOWN or INPUT_LEFT
-	dw	INPUT_RIGHT
-	dw	INPUT_UP or INPUT_RIGHT
-	dw  INPUT_DOWN or INPUT_RIGHT
-	dw	INPUT_UP_LEFT
-	dw	INPUT_UP_RIGHT
-	dw	INPUT_DOWN_LEFT
-	dw 	INPUT_DOWN_RIGHT
-@@case_to_target = $ - @@switch_table
-@@num_cases = @@case_to_target shr 1
-	; jump table for switch statement
-	dw offset @@standing_still
-	dw offset @@up
-	dw offset @@down
-	dw offset @@left
-	dw offset @@up_left
-	dw offset @@down_left
-	dw offset @@right
-	dw offset @@up_right
-	dw offset @@down_right
-	dw offset @@up_left
-	dw offset @@up_right
-	dw offset @@down_left
-	dw offset @@down_right
-player_move	endp
diff --git a/th04/main/player/move.cpp b/th04/main/player/move.cpp
new file mode 100644
index 00000000..968a15ea
--- /dev/null
+++ b/th04/main/player/move.cpp
@@ -0,0 +1,45 @@
+#pragma option -zPmain_01
+
+#include "platform.h"
+#include "pc98.h"
+#include "th01/math/subpixel.hpp"
+#include "th04/math/motion.hpp"
+#include "th04/hardware/inputvar.h"
+#include "th04/main/playfld.hpp"
+#include "th04/main/player/player.hpp"
+#include "th04/main/player/move.hpp"
+
+#pragma option -a2
+
+inline void move(int direction_x, int direction_y) {
+	if((direction_x != 0) && (direction_y != 0)) {
+		player_pos.velocity.x.v = (direction_x * playchar_speed_diagonal);
+		player_pos.velocity.y.v = (direction_y * playchar_speed_diagonal);
+	} else if(direction_x != 0) {
+		player_pos.velocity.x.v = (direction_x * playchar_speed_aligned);
+	} else if(direction_y != 0) {
+		player_pos.velocity.y.v = (direction_y * playchar_speed_aligned);
+	}
+}
+
+move_ret_t pascal near player_move(input_t input)
+{
+	move_ret_t ret = MOVE_VALID;
+	switch(input) {
+	case INPUT_NONE:                	ret = MOVE_NOINPUT;	break;
+	case INPUT_LEFT:                	move(-1,  0);      	break;
+	case (INPUT_DOWN | INPUT_LEFT):
+	case INPUT_DOWN_LEFT:           	move(-1, +1);      	break;
+	case INPUT_DOWN:                	move( 0, +1);      	break;
+	case (INPUT_DOWN | INPUT_RIGHT):
+	case INPUT_DOWN_RIGHT:          	move(+1, +1);      	break;
+	case INPUT_RIGHT:               	move(+1,  0);      	break;
+	case (INPUT_UP | INPUT_RIGHT):
+	case INPUT_UP_RIGHT:            	move(+1, -1);      	break;
+	case INPUT_UP:                  	move( 0, -1);      	break;
+	case (INPUT_UP | INPUT_LEFT):
+	case INPUT_UP_LEFT:             	move(-1, -1);      	break;
+	default:                        	ret = MOVE_INVALID;	break;
+	}
+	return ret;
+}
diff --git a/th04/main/player/move.hpp b/th04/main/player/move.hpp
new file mode 100644
index 00000000..30477a20
--- /dev/null
+++ b/th04/main/player/move.hpp
@@ -0,0 +1,19 @@
+// All values are signed. (Yes, allowing you to invert the controls with
+// negative values!)
+#if (GAME == 5)
+	extern subpixel_t playchar_speed_aligned;
+	extern subpixel_t playchar_speed_diagonal;
+#else
+	static const subpixel_t playchar_speed_aligned = TO_SP(4);
+	static const subpixel_t playchar_speed_diagonal = TO_SP(3);
+#endif
+
+enum move_ret_t {
+	MOVE_INVALID = 0,
+	MOVE_VALID = 1,
+	MOVE_NOINPUT = 2,
+};
+
+// Applies the given [input] to the player's velocity. Both games assume
+// [player_pos.velocity] to be (0, 0) prior to calling this function.
+move_ret_t pascal near player_move(input_t input);
diff --git a/th04/player_m.cpp b/th04/player_m.cpp
new file mode 100644
index 00000000..f06219d3
--- /dev/null
+++ b/th04/player_m.cpp
@@ -0,0 +1 @@
+#include "th04/main/player/move.cpp"
diff --git a/th04/th04.inc b/th04/th04.inc
index fb8cefed..4ebca5eb 100644
--- a/th04/th04.inc
+++ b/th04/th04.inc
@@ -48,7 +48,4 @@ resident_t struc
 		db 54 dup(?)
 resident_t ends
 
-playchar_speed_aligned = 4 shl 4
-playchar_speed_diagonal = 3 shl 4
-
 BOMB_INVINCIBILITY_FRAMES = 255
diff --git a/th04_main.asm b/th04_main.asm
index bf6331aa..ffdc5998 100644
--- a/th04_main.asm
+++ b/th04_main.asm
@@ -43,7 +43,7 @@ include th04/main/enemy/enemy.inc
 	extern _tolower:proc
 	extern __ctype:byte
 
-main_01 group SLOWDOWN_TEXT, ma_TEXT, DEMO_TEXT, EMS_TEXT, mai_TEXT, PLAYFLD_TEXT, main_TEXT, DIALOG_TEXT, main__TEXT, PLAYER_P_TEXT, main_0_TEXT, HUD_OVRL_TEXT, main_01_TEXT, main_012_TEXT, CFG_LRES_TEXT, main_013_TEXT, MB_INV_TEXT, BOSS_BD_TEXT, BOSS_BG_TEXT
+main_01 group SLOWDOWN_TEXT, ma_TEXT, DEMO_TEXT, EMS_TEXT, mai_TEXT, PLAYFLD_TEXT, main_TEXT, DIALOG_TEXT, main__TEXT, PLAYER_M_TEXT, PLAYER_P_TEXT, main_0_TEXT, HUD_OVRL_TEXT, main_01_TEXT, main_012_TEXT, CFG_LRES_TEXT, main_013_TEXT, MB_INV_TEXT, BOSS_BD_TEXT, BOSS_BG_TEXT
 g_SHARED group SHARED, SHARED_
 main_03 group GATHER_TEXT, SCROLLY3_TEXT, MOTION_3_TEXT, main_032_TEXT, VECTOR2N_TEXT, SPARK_A_TEXT, GRCG_3_TEXT, IT_SPL_U_TEXT, B4M_UPDATE_TEXT, main_033_TEXT, MIDBOSS_TEXT, HUD_HP_TEXT, MB_DFT_TEXT, main_034_TEXT, BULLET_U_TEXT, BULLET_A_TEXT, main_035_TEXT, BOSS_TEXT, main_036_TEXT
 
@@ -8661,9 +8661,13 @@ loc_10704:
 
 include th04/main/enemy/render.asm
 include th04/main/player/invalidate.asm
-include th04/main/player/move.asm
 main__TEXT	ends
 
+PLAYER_M_TEXT	segment	byte public 'CODE' use16
+	@PLAYER_MOVE$QUI procdesc pascal near \
+		input:word
+PLAYER_M_TEXT	ends
+
 PLAYER_P_TEXT	segment	byte public 'CODE' use16
 	_player_pos_update_and_clamp procdesc near
 PLAYER_P_TEXT	ends
@@ -8830,9 +8834,9 @@ loc_10B11:
 		mov	[bp+var_1], 1
 
 loc_10B32:
-		call	main_01:player_move pascal, si
+		call	@player_move$qui pascal, si
 		mov	[bp+@@move_ret], al
-		cmp	[bp+@@move_ret], 0
+		cmp	[bp+@@move_ret], MOVE_INVALID
 		jnz	short loc_10B58
 		cmp	[bp+var_1], 0
 		jz	short loc_10B58
diff --git a/th05/player.asm b/th05/player.asm
index 095dabfc..81854829 100644
--- a/th05/player.asm
+++ b/th05/player.asm
@@ -84,9 +84,8 @@ PLAYER_INVALIDATE	endp
 	even
 
 
-; move_ret_t pascal near player_move(int input);
-public PLAYER_MOVE
-PLAYER_MOVE	proc near
+public @PLAYER_MOVE$QUI
+@player_move$qui proc near
 arg_bx	near, @input:word
 
 @@diagonal_x equ ax
@@ -183,7 +182,7 @@ arg_bx	near, @input:word
 	dw @@invalid
 	dw @@invalid
 	dw @@down_right
-PLAYER_MOVE	endp
+@player_move$qui endp
 MAIN_01_TEXT	ends
 
 	end
diff --git a/th05_main.asm b/th05_main.asm
index 73503379..3e43675b 100644
--- a/th05_main.asm
+++ b/th05_main.asm
@@ -7050,7 +7050,7 @@ loc_12188:
 		mov	[bp+var_1], 1
 
 loc_121A9:
-		call	player_move pascal, si
+		call	@player_move$qui pascal, si
 		or	al, al
 		jnz	short loc_121CA
 		cmp	[bp+var_1], 0
@@ -7818,7 +7818,7 @@ sub_12842	endp
 	SHOT_YUUKA_L8 procdesc pascal near
 	SHOT_YUUKA_L9 procdesc pascal near
 	PLAYER_INVALIDATE procdesc pascal near
-	PLAYER_MOVE procdesc pascal near \
+	@PLAYER_MOVE$QUI procdesc pascal near \
 		input:word
 	HUD_BAR_PUT procdesc near
 	HUD_SCORE_PUT procdesc near