No revenue estimate for GOG — its rating/review counts don't calibrate to sales the way Steam's do. The Steam version is estimated at $4.2K — a different platform, not this one.

Hellfire

Toaplan Arcade Shoot'em Ups 2 bundle ALIENS BLAST YOU FROM ALL DIRECTIONS! HELLFIRE is Toaplan's first side-scrolling shooter! This PC port of the celebrated 1989 arcade title features online leaderboards, arcade-accurate emulation, quick saves, and more. You'll face a blood-boiling trial of complex choices, blazing graphics, and aliens ambushing from every angle. Firepower alone won't cut it; you must use your weapons strategically and with great prowess! "Desperate to regain the six planets stolen by the sinister Guild Empire, the kindhearted Captain Lancer of the rebelling forces unleashes a superheated space battleship: HELLFIRE! Its blinding firepower marks the beginning of an all-out war between good and evil." ORIGINAL GAME FEATURES: Choose Fire Direction: Rotate through eight shooting directions of four mighty weapons and unleash a whirlwind of hell. A strategic mindset is required, but once you master this system, you'll wonder how you lived without it. Co-op Mode: Play alone or with a friend! Wildly creative graphics: Explore a world of stunning vistas, mighty machines, and deadly enemies. If you can't handle the heat, at least you'll go down in style… The rock-heavy soundtrack by Tatsuya Uemura showed a different side of Toaplan in the 80s, and it’s still headbang-inducing today. QUALITY OF LIFE IMPROVEMENTS: Minimal Input Lag: Emulation, input processing, and rendering all complete on the same frame. Quick Save using F1-F10, Reload with Shift+ F1-F10 Online leaderboards for Single Credit, No Assist, and Assisted plays. Instrument panels with extra gameplay information and artwork. Rewind the game between 10-18 minutes, depending on the action. Experience the game in Mirror Mode Capture sharable replays to immortalize your interstellar victories (or funny moments). Assist Features such as auto-fire at multiple rates. Very Easy Mode: Lower the difficulty to breeze through the adventure. Pixel perfect or full-screen scaling in windowed or full-screen mode. Rotate the gameplay in 90-degree increments. Achievements Hone your skills in the ultra-customizable practice mode!