Looking at the video... it didnt seem all that difficult. Then I read that you had a dual control system... and that definitely helps. Still, enemy vigilance did not really seem there... for an arcade level game.
Sega Master system has a game called "SDI" It used the same kind of control system. You pilot a satellite, and try to avoid being shot at... while shooting down invaders and missiles. You can move the Sat... or press a button to enable you to move the crosshair to direct your fire stream. Wizball seems to be similar to this + Fantasy Zone.
The arcade version of SDI has a trigger stick for the Sat. , and a trackball to aim.
I believe Dual controls rally help keep the intensity of games difficulty... and fun factor.
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Top Favs that could have done great in the Arcade:
Sega Master System - Shooting Gallery
This game is similar to Point Blanc. Except, IMO, is more fun to play. IMO, best lightgun game ever made.
(Missile Defense 3d, in 3d... was also an awesome lightgun game. Though, I still preferred Shooting Gallery)
Sega Genesis - Target Earth
This game is Arcade Tough. Similar to the Difficulty in the Williams games, like Defender. I think it took me several hours to figure out how to survive and destroy the first level ship. The soundtrack is amazing. The weapons are wicked. Great storyline. Even an amazing Cinematic to show the story... if you dont start the game up right away.
Sega Genesis - Thunderforce II
This game got a bad rap because of the top view sections. With a slight modification to them... making them more linear than a free roaming map.. it would easily have dominated in the arcade. The side-view shooting action is intense.. yet unlike some other shooters such as R-Type... you can still do fine if you get killed and lose your powerups. The game has Excellent balance. Its fun, rather than frustrating. I like that its not a "Bullet-Hell" game. The bullets move very quickly... keeping you on your toes. Far more realistic to projectiles.
It took me like a year of off and on play to finally beat it. (Starting from level 5? using the secret menu level-select) I still love to fire a game up and play again, so the replay value is good.
The musical score and sound effects are probably the best of any game Ive played on that system. Some of my favorites period.
There is also a more advanced version, on the X68000 computer. It has more graphic detail, more scrolling layers, more levels. They made one of the bosses on the Genesis version more difficult, to make up for the level losses.
While Thunderforce III has its moments... IMO, its graphically and playably inferior to TFII. Lower Resolution graphics, lower sound quality in the music and sound effects. Far easier difficulty level (I beat it the first day I owned it. Ugg)
Amiga - Battle Squadron
Gorgeous 2 Player co-op Vertical Shooter. Great gameplay similar to Raiden.. but with more substance.
Great music & SFX. Cool visual effects, such as cloaking ships. Mild difficulty at the top level... and very difficult sections underground.
PC - Platypus
This could easily be put on-location and make money.
2 player co-op side scrolling shooter. Great claymation. Good gameplay. Good difficulty balance. Nice remix c64 tunes.
PC - Minicar Racing (E-Games)
This Gem is a very fun racing game similar in vein to RC Pro-Am. It supports up to 4 players at once. Its wicked fun, and quite challenging.
I think a form of this could have done well with a little tweaking.
C-64 The Last V8
This game has an Ominous Psychological presence. Its 1st level is very difficult, intense, and scary. With some adaptation, arcade controls, larger levels..etc.. it has potential for greatness. ( I wasnt a fan of the lower levels though .. too slow and narrow)
C64 - Raid over Moscow
Hmm, as far as I recall, this was a pretty fun game with a lot of interesting variations. May have had a nice shot.