diff --git a/dosdl.asm b/dosdl.asm
index 65c4719..09b298f 100644
--- a/dosdl.asm
+++ b/dosdl.asm
@@ -9,9 +9,60 @@ args_area equ 0x81
 section .code
 
 parse_arguments:
-	; TODO: Implement argument parsing
 	xor ch, ch
 	mov cl, [args_length]
+	mov si, args_area
+
+	; Skip leading spaces
+	.skip_leading_space:
+		test cx, cx
+		jz .leading_spaces_skipped
+		cmp byte [si], ' '
+		jne .leading_spaces_skipped
+		dec cx
+		inc si
+		jmp .skip_leading_space
+
+		.leading_spaces_skipped:
+
+	; See whether we have /h or /u
+	cmp cx, 2
+	jb .not_mode_option
+	cmp byte [si], '/'
+	jne .not_mode_option
+
+	cmp byte [si + 1], 'h'
+	jne .not_hard_mode
+
+	.hard_mode:
+		mov byte [hard_mode], 1
+		add si, 2
+		sub cx, 2
+		jmp .after_option_space
+
+	.not_hard_mode:
+	cmp byte [si + 1], 'u'
+	jne .not_ultra_hard_mode
+
+	.ultra_hard_mode:
+		mov byte [hard_mode], 1
+		mov byte [ultra_hard_mode], 1
+		add si, 2
+		sub cx, 2
+
+	.after_option_space:
+		test cx, cx
+		jz .option_done
+		cmp byte [si], ' '
+		jne .option_done
+		dec cx
+		inc si
+		jmp .after_option_space
+
+		.option_done:
+
+	.not_ultra_hard_mode:
+	.not_mode_option:
 
 	test cx, cx
 	jz seed_rng_date
@@ -243,10 +294,11 @@ check_targets:
 		loop .targets_loop
 
 word_not_found:
+	mov si, not_found_str
+
+print_error:
 	mov ah, 9
-	mov dx, space_dash_space_str
-	int 0x21
-	mov dx, not_found_str
+	mov dx, si
 	int 0x21
 
 	; Wait for a keypress
@@ -262,7 +314,6 @@ word_not_found:
 	mov dx, erase_word_str
 	int 0x21
 
-	mov si, not_found_str
 	.clear_loop:
 		lodsb
 		cmp al, '$'
@@ -274,7 +325,7 @@ word_not_found:
 
 		jmp .clear_loop
 
-	.done:
+		.done:
 
 	mov ah, 2
 	mov dl, 13
@@ -780,6 +831,9 @@ guesses db 0
 
 dictionary_entry times 5 db 0
 
+hard_mode db 0
+ultra_hard_mode db 0
+
 rng_seed dd 0
 rng_t dd 0
 
@@ -801,7 +855,7 @@ section .rodata
 greeting_str db 'Welcome to hello DOSdl. Run `dosdl /?` for help.', 13, 10, '$'
 
 space_dash_space_str db ' - $'
-not_found_str db 'word not found$'
+not_found_str db ' - word not found$'
 erase_word_str db '     $'
 word_was_str db 'The word was: $'
 correct_in_str db 'Correct in $'