Level select
 
 Select "Sonic & Knuckles", choose any character, and play "Angel
 Island". Jump and hang on a swinging vine. Then, press [Left],
 [Left], [Left], [Right], [Right], [Right], [Up], [Up], [Up]. If you
 entered the code correctly, you will hear a sound.
 
 Sound test
 
 Enable the "Level select" code. Then, restart the game using the
 option under the "File" menu. Now at the title screen, press [Down],
 [Down]. 
 
 Screen capture
 
 While playing a game, press [F9] to save an image of the current
 screen in the game directory.
 
 Super Sonic
 
 Collect all seven emeralds, then accumulate fifty rings or a single
 bonus. Then, quickly jump twice in succession.
 
 Sonic special stages
 
 Enter the following codes on the special stage screen.
 
 Level   Code
 2       2965 3192 9023
 3       3610 2354 7327
 4       2921 0274 3999
 5       3737 7423 1487
 6       3053 9029 9071
 7       3698 8191 7375
 8       3009 6111 4047
 9       3482 7286 3167
 10      2809 6267 2575
 11      3454 5929 0879
 12      2765 3348 7551
 13      3582 0497 5039
 14      2898 2104 2623
 15      3543 1266 0927
 16      2853 9185 7599
 17      4014 2308 3455
 18      3319 6540 9215
 19      3964 5702 7519
 20      3275 3622 4919
 21      4092 0771 1679
 22      3408 2377 9263
 23      4053 1539 7567
 24      3363 9449 4239
 25      3837 0634 3359
 26      3163 9615 2764
 27      3808 8777 1068
 28      3119 6696 7740
 29      3936 3845 5228
 30      3252 5452 2812
 31      3897 4614 1116
 32      3208 2533 7788
 33      2994 5155 4236
 34      3673 9888 9404
 35      2944 5155 4236
 36      3629 6970 4380
 37      3072 0223 8396
 38      3762 5728 9452
 39      3033 0992 4284
 40      3718 2807 4428
 41      2817 0087 0076
 42      3518 2963 2956
 43      2788 8229 7788
 44      3474 0044 7932
 45      2916 3298 1948
 46      3606 8800 3004
 47      2877 4066 7836
 48      3562 5881 7480
 49      3348 5109 0364
 50      4028 3236 9596
 51      3298 8503 4428