Galactic Invaders

Galactic Invaders: Sigma Seven v1.22

An Amiga game heavily inspired by Galaga in Amiga graphic style. I dreamt of an Amiga shoot 'em up that had to feel arcade-like and could work on the Amiga 1000 with A1050 front-panel 256K expansion or on a stock Amiga 500 with base 512K, something that could be used in shop windows as a showcase of Amiga in 1987. I didn't want a port of Galaga—there already are some ports—I wanted a game that felt 100% Amiga in style and appearance. Also, I know there are some excellent revisitations like Deluxe Galaga (which is a great game, more in the style of a "computer" game), but I wanted a game that makes you feel in the arcades with your freshly acquired Amiga lets say around 1987, but even in late 1985, lol. It nonetheless works on other Amiga models too.

This is version 1.22 and I could improve it further in the near future.

Gameplay Features

• Classic & New: The game features intense boss fights, challenging stages, and a ship-stealing mechanic (à la Galaga).
• Dynamic Ship Transformation: A unique mechanic built for boss battles. For example, when fighting a mid-tier boss like DON KAISER—who floods the screen with projectiles and minion ships—having a standard "dual ship" formation would normally mean losing a ship instantly due to the larger hitbox. To solve this, your two ships will automatically fuse into a single, more powerful craft. This allows you to easily dodge dense bullet patterns while maintaining maximum firepower.

A Note on the Development Process

Thank you so much for all the downloads on my previous games! The game has been designed by me and made with AI-assistance. However, as many developers know, working with AI isn't just about pressing a button or entering a quick prompt. It requires countless hours of exhausting sessions, endless trial and error, missteps, and constant refinement. It shifts the effort from manual execution to heavy technical and artistic direction—shaping the AI's output until it perfectly matches the vision in your head. It’s a labor of love, and I’ve poured a lot of time into making it just right.

If you like my work and want to support future projects, please consider buying me a coffee at: https://ko-fi.com/peppe74. Every bit of support makes me happy and helps keep these projects going!

Galactic Invaders: Sigma Seven – v1.22 update

The game has a new name! It’s now Galactic Invaders: Sigma Seven, with a redesigned chrome logo.

New content

• 9 different Challenging Stages: spiral, wave, X-cross, rings, zig-zag, figure-eight, arc, comet and the classic one. They come in a fixed sequence, and some feature the transformed enemies too.
• 6 entry choreographies for normal stages, rotating stage by stage: loops, hooks, swoops, teardrop dives and more.
• New music and jingles:
  • game start fanfare
  • “fighter captured” tune
  • PERFECT fanfare
  • Challenging Stage results jingle
  • boss destroyed victory fanfare
  • dedicated high score entry music; challenge stages music (circus style)

Gameplay and balance

• Fewer enemy bullets up to stage 10. Stage 1 is now as tough as stage 2.
• DISCOBLASTER is tougher: its cannons and core take more hits.
• Fixed a boss that could circle endlessly during its tractor beam dive, or fire an invisible beam near the left edge.

Technical

• PAL only. NTSC ECS Amigas switch to 50 Hz automatically. Older NTSC OCS machines show a “PAL ONLY” message.
• Fixed text glitches on the results and name entry screens, and redrew the % symbol.

Requires an Amiga 500 with 512K chip RAM, or an Amiga 1000 with an A1050 expansion. Have fun!