MEGAKO☆PUNCH!, which brings blackjack’s rules straight into a deck-building roguelite, launched on Steam on August 10, 2026, Japan time. Everything from development to sales was handled solo by Japanese indie developer Mononobe Monoko (@mononobe_monoko).

The number 21 sits at the core of the gameplay. Players flip cards onto the field, and when the total cost hits exactly 21, they can trigger メガ子パンチ. Players can also return cards they’ve played back to their hand, letting them fine-tune the total so it doesn’t go over as they aim for 21. The game includes 64 types of cards and 15 types of items, which players combine to defeat enemies.

The Steam store page describes the game as: “A Blackjack-inspired deckbuilding roguelite! Hit exactly 21 to unleash powerful Ultimate Cards! Beat your enemies to a pulp with utterly broken combos!” In this English text, the special-move cards are called Ultimate Cards. The store page also features a video labeled “Trailer.”

Both development and publishing are credited to Mononobe Monoko, and the Steam store page lists the same name in both the developer and publisher fields. In an official press release, Mononobe Monoko described what mattered most in making the game: “I love that moment when you’re playing a new card game and realize, ‘Oh, with these rules, this kind of card must be strong.’ That’s why, in this game, I cared not just about how flipping and returning cards feels, but also about the flash of insight and satisfaction that comes from combining cards with unusual effects.” (translated from Japanese)

The game is available on PC via Steam, and it is Windows-only. It supports two languages, Japanese and English. Because it supports English, players who don’t read Japanese can play it as is. Steam has 19 user reviews for the game, and all of them are positive. That review count is still small.