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 $3.2K — a different platform, not this one.

Death Kid

Death Kid is an arcade-inspired arena brawler with meta progression where skill and strategy are crucial. Break through eight seals to reach the bottom of a treacherous well with the help of three souls trapped between life and death. Protect them at all costs, take out hordes of relentless enemies and fight your way to put the wheel of life and death back in motion.     Step into the role of the cryptic Death Kid – a protagonist cursed with immortality. Engage in close-quarters combat, master a variety of powerful abilities and grow stronger with each run. Stay agile, think fast and devise the right strategy to annihilate your enemies. Let the rage fill you up and unleash the fury upon otherworldly creatures that want to see you fail.     Try again and again to reach the bottom of the well with some help from a mysterious stranger. Gain experience and unlock new abilities hidden in The Book of Death to go further and further with each attempt.   Clear eight floors – each swarming with a different set of relentless monsters. Try to keep the enemies at bay as they draw closer and closer to the center, hungry to drain the life that still lingers inside the souls. Be careful – they will stop at nothing to break you. But there might be a way to use them to your advantage…   Skill-based combat, responsive controls, challenging enemies – everything you need to get the adrenaline going. What more could you ask for?   Descent through 8 levels – each swarming with a set of unique enemies and unveil the mystery of life and death Protect 3 fragile souls giving them enough time to open up a passage leading further down the well Give yourself a boost by flawless gameplay to progress faster and triple your experience gain Fill your rage to transform into an even deadlier form Increase your strength with 15 levels of passive skills Discover 6 upgradable abilities with new effects  Interact with a mysterious stranger acting as your guide and mentor Use special abilities of your enemies to your advantage Enjoy engaging and entertaining side events between the runs Difficulty settings - Easy and Normal Endgame challenge mode