Press F1 on options menu for more balls.
While playing, press ESC.  When asked to quit, press J.
To get 2 Balls and also have control over ball press ESC, B, then J.
You can make the flippers "stick" by pressing "X" and "/"

These debug codes in the shareware version will help you have
some fun with the game. All codes need to have escape (ESC) to
be pressed first for the prompt; the responses to this prompt
activates the cheats.  (The escape is included for quick reference.)

Codes          Purpose
---------------------------------------------------
ESC-B-N    An extra ball is dropped during play.

ESC-J        Using the cursor keys, the ball is  under player control.

ESC-F9      A border appears. (Does not work for all monitors.)

ESC-F10    A screen capture to file SCREEN.PCX.

ESC-F1      A parameter request prompt. (Unknown parameters)
 

For unlimited balls, jump to dos and do this:
-----------------------------------------------------------------
DEBUG CONFIG.PIN
e10b
00
w
q
 

For unlimited balls in all of the tables (registered):
--------------------------------------------------------------------------
Be sure that the ep*.exe are not packed with exe-compressors
like pklite or lzexe!

file/table    file-offset (hex/dec) original (hex)

ep1.exe/ANDROID        34D0D/216333  FE 06 37 68
ep2.exe/POT OF GOLD    36AD1/223953  FE 06 58 55
ep3.exe/EXCALIBUR      336B7/210615  FE 06 C1 4D
ep4.exe/CRASH AND BURN 338C8/211144  FE 06 55 59
ep5.exe/MAGIC          3049D/197789  FE 06 D2 43
ep6.exe/JUNGLE PINBALL 37FF6/229366  FE 06 BB 60
ep7.exe/DEEP SEA       34358/213848  FE 06 1E 55
ep8.exe/ENIGMA         37932/227634  FE 06 AE 4F
ep9.exe/CYBORGIRL      33BFF/211967  FE 06 77 41

overwrite the original bytes with 90 90 90 90. now you should
play pinball with umlimited balls.