-The SEGA logo is the one most Genesis games have, but is colored darker blue.

-The intro sequence consists of the Feather 1 spinning around, whilst several lines of text saying the same thing appear. There is no music either.

-The game's title graphic is different, and the game is called Stellar Assault even if you have your emulator's region set to USA.

-The words in the options menus are very dark and harder to read.

-You can only set the enemy ship colors to green or magenta in this build, however, it doesn't seem to work anyway as ships change colors between missions.

-There is a normal difficulty setting in the options menu.

-The left and right rotation buttons are reversed, so X is right and Z is left.

-No sound is played each time you cycle through an option.

-The sound effect played for entering and exiting option menus is different.

-The sound test is very basic looking. This build doesn't let you stop tracks after starting them either. A few pieces of music are not present in this build.

-The object viewer does not have proper names for any ship yet, instead, everything is referred to as an object followed by a number. The ships seen in Feather 2's launch sequence and the Ganeluza ship cannot be viewed. The booster ship is shown later in the list.

-The object viewer lets you view the final boss.

-The ship selection screen is very plain, featuring an all black background.

-The ships don't have their special weapons yet.

-The ship launching sequences features different colors on the floors (for the Feather 2), and different colored lights on the runway.

-Before taking off, some of the ship checks have different names, such as "CENSOR" instead of "SENSOR".

-The words "SYSTEM IS ALL GREEN" appear after the ship checks are completed. This text is followed by "READY TO TAKEOFF".

-The warp gates your ship passes through after blasting off have green colors on them.

-Feather 2's launch features two larger ships moving around, these aren't present in this build.

-During the mission briefing, a small picture of the Feather 1 will be shown even if you are flying in the Feather 2.

-The briefing screens have a few little differences in them, such as "JUMP OUT COORDINATE" instead of "JUMP OUT COORDINATES" and "ELIMINATE ALL TARGETS" instead of "ELIMINATE THE TARGETS".

-The briefing screen also ends with "GOOD LUCK TO YOU!" in this build, this would later be changed to just "GOOD LUCK!"

-Pressing Start during a briefing skips it in this proto, whilst A, B and C go through the text.

-The sound effects in this proto are very bad, such as the PEW PEW PEW lasers, and the engine noises are really poor.

-Pressing the mode button will send you to the next level! Your ship may spend several seconds flying around weirdly, but eventually you'll warp. Because of this, it doesn't seem possible to change views in this build.

-If you don't mess with the color settings in the options menu, their colors will alternate between green and magenta during gameplay. They stay green for the first few levels, but for a couple of levels they'll be magenta.

-The music used for level 5 is what the final uses for level 6 (before the cannon opens up).

-The music used for level 6 is what the final uses for when the cannon opens up and the final boss fight begins.

-The Ganeluza cruiser in level 5 doesn't seem to be able to fire at you, and has different colors.

-There is no time limit in level 6.

-The first wave of slave units in level 6 don't fire at you. The second wave, however, do.

-The final boss has different colors.

-Beating the game has it reset, no ending sequence is in place. Although the music that should be heard for the ending and credits can be heard in the sound test.

-The ships seem to be able to take a lot more damage, and the Feather 1's guns do a lot of damage to the big ships.

-The way the title appears is slightly different in this build, as it appears in a flash of light.

-The menu text is brighter.

-The sound test menu has some additional graphics in it, used for when a track is played. Some extra music has been added.

-The object viewer now lets you view the warp gates your ship takes off through, and the Ganeluza cruiser can now be viewed. The 10th object is a ship that couldn't be viewed in the previous build.

-Level 5's music has been changed to what the final version uses.

-Level 6's music has now been changed to what the final version uses.

-The first wave of slave units now fire at you in level 6.

-The ending and credits sequences have been added.

-The credits feature a slightly different font, with chunkier letters. A lot of the names in the credits are different.

-The music used during the credits is quite a bit slower than the final version's.

-The game doesn't reset when the credits are over, and instead just stays on a screen of space and stars.

-If the game goes into demo mode, a "MCTV 64" logo has been added to the top right corner of the screen. It flashes on and off throughout the demo.

-The flippy SEGA logo has been added.

-When cycling through the options at a menu screen, a sound is played.

-The sound test has been changed, and now matches what the final version has.

-A massive, 3D SEGA logo has been added to the object viewer.

-Some new sound effects have been added, whilst some have been removed.

-Some colors have been changed, such as Feather 2's speed gauge now being green instead of red.

-Feather 2's launch sequence now features blue ground around the runway.

-The Ganeluza cruiser in level 5 will now fire at you.

-The unique font used for Artmic's credit has been added.

-The music used for the credits has been sped up to match what the final version uses.

-Some of the green letters used in the credits are less chunky.

-The credits now end with the large SEGA logo appearing, something the previous proto didn't have. However, the SEGA logo flashes white and blue.

-The game will now reset after the credits finish.

-The MCTV 64 logo used during the demo has been changed.

-The title screen animation has gone back to what it was in the first prototype (and what it will be in the final game).

-Some copyright text has been added to the title screen.

-Color change mode has been added, and is a separate menu accessed in the options screen. However you cannot actually see the colors of the ships yet.

-The G.L. cannon (final boss of the game) and Ganeluza cruiser have had color changes, matching what they are in the final game.

-The lights featured on the runways and warp gates have had their colors changed to match the final version's.

-The ground around Feather 2's runway has been changed, from blue to gray, like the final version has.

-A lot of text has been updated. For example, the "CENSOR" check has been changed to "SENSOR". "SYSTEM IS ALL GREEN" is now "ALL SYSTEMS OPERATIONAL", "READY TO TAKEOFF" is "READY FOR TAKEOFF" etc.

-Pressing B during a mission briefing will end it, whilst pressing start will now pause the game instead of skipping the briefing.

-The targeting computer displays have been changed to black (which was useless, as you could rarely ever see it due to most of the background being black) to red.

-The intro has been slightly updated -the "DATA NOT" stuff has been removed.

-Some sound effects have been changed.

-The color change menu has been updated.

-The object viewer has been updated, and now has actual names for each ship. The warp gates, G.L. Cannon and SEGA logo can no longer be viewed.

-Ship A and ship B have been added to the object viewer, and now appear during Feather 2's launch sequence.

-The object viewer calls the support ship (that appears between each of Feather 1's missions) "SUPPORT DEVISE"

-The level skip cheat no longer works, and the mode button now does nothing -you still can't change view.

-The intro has been updated and now matches what the final game has.

-The title screen has been changed, featuring a new font for the logo. This title screen would be used for the final Japanese and European versions of the game.

-The MCTV 64 logo has been removed from the demos. It would be restored for the Japanese final version however.

-The normal difficulty level has been removed.

-A cursor speed option has been added to the options menu.

-The color change menu has been updated again, so it now displays some ships that will change color when you edit the options.

-The object viewer's "SUPPORT DEVISE" is now "SUPPORT SHIP".

-Pressing the mode button will change your view.

-If you set your emulator's region to USA, the game's title screen will now be "Shadow Squadron".