Did you ever check out the porn games in MAME? If so, you probably realized that the mahjong games are, well, mahjong, and that 99% of the rest of them are utter bullshit. The Gals Panic series, however, combined mild porn with actual fun gameplay and as such sticks out in the MAME collection of porn. The gameplay is pretty much Qix (or rather Qix II) straight up without much in the way of new ideas, sure, but still fun.
Unfortunately, the designers at Kaneko made the choice to make GP a credit-munching series. It's literally impossible, or at least takes an ungodly amount of skill, to survive for longer than a few minutes in Kaneko's version of the games.
This is where homebrew devs (I'm guessing?) D5 come in with their PC adaptation "Gal PaniX". It does GP better than the original devs ever did. The artwork is much better, whereas Kaneko's was mediocre at best. The music also rocks, as does the presentation with a decent amount of game modes (3) and many galleries (etc) to unlock by playing well. Best of all, though -- the game is actually playable. You have a very fair shot at making it not only through a few minutes, but a full run through the game.
So, to summarize:
Gals Panic == Boobies + Qix + fun + impossible + annoying
GalPaniX == Boobies + Qix + fun - impossible - annoying
And as a side note, I'm gonna point out that GalPaniX is nothing less than an orgy of references for shooter fans to pick up on. It's kind of an odd choice, but seeing as how Kaneko steered GP towards including shooter elements in Gals Panic 4 and up, I guess D5 just figured they'd go all out. The references are very clear tributes, and I've had a lot of fun spotting stuff from Gradius, R-Type, Battle Garegga, Cave games, Psyvariar, 194X, and many others I'm too tired to remember right now.
So yeah. It's actually a pretty fun puzzler, even if you're not in it for the cartoon panty shots, too.
Download! (Click the "download" link. Full game, use WinRAR.)
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The D5 guys also made a top-down run n' gun game, like Shock Troopers or Mercs, but it isn't finished yet. It has no music and needs some tweaks, but the idea is still pretty cool and worth checking out for a few minutes.
Download! (Click the three kanji link, right under the first "Gauntlet".)