This is pretty standard MPAGD intro menu, but I've added the redefine keys commands, always let your player redefine their keys!
(note that in V1 of Shmupkit my comments on the key redefines are wrong, the correct ones are below...it still works though....was a copy and paste error on my part!)
EVENT INTROMENU
WAITKEY
BORDER 0
COLOUR 68
CLS
LET CONTROL = 99
WHILE CONTROL >= 99
PRINTMODE 1
AT 4 6
PRINT "MPAGD SHMUPKIT DEMO"
AT 18 5
PRINT "minilopretro.com 2022"
PRINTMODE 0
AT 8 10
PRINT "1. KEYBOARD"
AT 10 10
PRINT "2. KEMPSTON"
AT 12 10
PRINT "3. SINCLAIR"
AT 14 10
PRINT "4. REDEFINE"
LET CONTROL = 99
WHILE CONTROL = 99
IF KEY OPTION1
LET CONTROL = 0
ENDIF
IF KEY OPTION2
LET CONTROL = 1
ENDIF
IF KEY OPTION3
LET CONTROL = 2
ENDIF
IF KEY OPTION4
CLS
WHILE KEY OPTION4
ENDWHILE
AT 7 12
PRINT "PRESS KEY FOR:"
AT 9 12
PRINT "LEFT"
DEFINEKEY LEFT ; the key pressed will be the new Left key
AT 11 12
PRINT "RIGHT"
DEFINEKEY RIGHT ; the key pressed will be the new right key
AT 13 12
PRINT "THRUST"
DEFINEKEY UP ; the key pressed will be the new up key
AT 15 12
PRINT "FIRE"
DEFINEKEY FIRE1 ; the key pressed will be the new fire key
AT 17 12
PRINT "PAUSE"
DEFINEKEY FIRE3 ; this will be the PAUSE key
LET CONTROL = 100
CLS
ENDIF
ENDWHILE
ENDWHILE
CLS