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 $2.9K — a different platform, not this one.

Twin Hawk

CALL IN A FORMATION OF FRIENDLY FIGHTER PLANES AND FILL THE SKY WITH BULLETS. A vertical scrolling shooter game where you fight a conquering enemy. Defy the oncoming army and navy barrages! Rest assured, you are not alone; you can call up a formation of six friendly fighters. Even though powerful enemies like tanks and battleships don't require as much reflexes, the player must take a strategic approach. This makes Twin Hawk easy to play for players who aren't familiar with Toaplan's diverse lineup of shoot ‘em ups. Once the last stage is cleared, the game enters round 2 and returns to the first stage, but with each loop, the difficulty level increases and there are more bullets to dodge. Like the Japanese title of the game Daisenpu (Great Whirlwind) implies, the game will eventually come roaring into you with full force! The story of Twin Hawk: “In the year 193x, a fascist conquest of R country was planned. A small city, S City, developed from an oasis, was targeted as an experimental model area for the plan. The conquering army attacked the city, and the people, who had no way to accomplish anything, united the Daisenpu (Great Whirlwind) as an anti-conquest flying squadron to fight against the conquering army. And now, without waiting for the base to be completed, they took off.” ORIGINAL GAME FEATURES: Call for Backup: Six friendly planes flying in formation can be called in and provide back-up fire. Deadly Destructive Power: Call up the friendly fighters and press the button again before forming a formation, and the friendly fighters become a bomb with deadly destructive power. Two-player Tango: The international version of Twin Hawk brings two-player co-op action. 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. Rewind the game between 10-18 minutes, depending on the action. 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. Hone your skills in the ultra-customizable practice mode!