1989年，SEGA Master System在北美率先推出《神奇男孩III：龍之陷阱》（モンスターレアー ワンダーボーイIII/Wonder Boy III: The Dragon's Trap）。這是一款由Westone Bit Entertainment開發的橫向動作角色扮演遊戲。Hudson在1991年將其移植到PCE主機上，而TurboGrafx-16的北美版遊戲名稱則為「Dragon's Curse」。

在1992年Game Gear版發行時，更名為《Monster World II》：龍之陷阱 (モンスターワールドII ドラゴンの罠 / Monsutā Wārudo Tsū: Doragon no Wana) 。該遊戲之後被收錄在收藏集神奇男孩合輯中，在PS4、PS5跟Switch都有販售。

遊戲敘述在《神奇男孩 雅莎在怪物世界》(Wonder Boy in Monster Land)的故事結束後，主角神奇男孩進入機械飛龍（Meka-Dragon）的巢穴，準備消滅它。然而，他卻觸發詛咒，變成半人半獸的蜥蜴人。為破解詛咒，必須擊敗難纏的敵人，獲得老鼠、食人魚、獅子及老鷹的六種變身能力。最終要打敗血鬼龍，取得火蜥蜴十字架，才能變回真正的人類。

使用金幣來購買更好的裝備和武器，醫院可以幫助恢復體力。收集魅力石或裝備，某些物品可以增加「魅力」，這樣才能購買有問號的物品。狀態頁面會顯示目前的攻擊力、防禦力和魅力值。

透過方向鍵進行左右移動，按鈕用於攻擊和跳躍。透過方向鍵和攻擊按鈕可以使用副武器。初期需要攜帶較多的生命藥水，去小鎮的教堂可以取得續關的密碼。

遊戲的舞台包括水下、沙漠、叢林、洞穴和天空。每個舞台的最後都有一個頭目，擊敗就能取得他的能力。例如，老鼠人可以在特定的牆壁或天花板上行走，食人魚人可以在水下移動，獅子可以用劍攻擊敵人，老鷹則可以在空中飛翔。

當用完所有的接關次數時，可以在排行榜的名稱輸入「68K」，下次開始挑戰時續關次數就不會有限制。

遊戲的難度相當高，對於一些技術高超的玩家，可以在排行榜輸入同樣的名字五次，這時困難度就會進一步提升。

如果挑戰失敗也不用氣餒，可以在出現Game Over的字樣時按左、右、下、上、選擇、左，這時就能從上一個挑戰成功的舞台再次出發。

如果想要啟動音效測試，在標題畫面出現時按I、II，同時按RUN。透過方向鍵來更改數據。

要讓男女主角合體，先連結多頭搖桿插頭，用2P開始遊戲後按暫停。在拔去多頭插頭後，再繼續遊戲，這時兩人就會重疊後合體。

In 1989, SEGA Master System released the first edition of "Wonder Boy III: The Dragon's Trap" (モンスターレアー ワンダーボーイIII/Wonder Boy III: The Dragon's Trap) in North America. Developed by Westone Bit Entertainment, the game was later ported to the PCE console by Hudson in 1991, with the North American version for TurboGrafx-16 titled "Dragon's Curse."

When the Game Gear version was released in 1992, it was renamed "Monster World II: The Dragon's Trap" (モンスターワールドII ドラゴンの罠/Monsutā Wārudo Tsū: Doragon no Wana). The game has since been included in the Wonder Boy Collection, available for sale on PS4, PS5, and Switch.

The game's narrative unfolds after the events of "Wonder Boy in Monster Land," where the protagonist, Wonder Boy, enters the lair of the mechanical dragon (Meka-Dragon) to defeat it. However, he triggers a curse and transforms into a lizard-man, a creature with a half-human, half-beast form. To break the curse, he must defeat formidable enemies and acquire the six transformation abilities of Mouse (climbing walls), Piranha (swimming), Lion (heavy chopping), and Eagle (flying). Ultimately, he must defeat the Vampire Dragon and obtain the Fire Lizard Cross to return to his human form.

Players use coins to purchase better equipment and weapons, while hospitals help restore health. Collecting charm stones or equipping certain items increases "charisma," allowing the purchase of items marked with a question mark. The status page displays current attack power, defense power, and charisma level.

Movement is controlled by arrow keys, with buttons used for attacking and jumping. The directional keys and attack button allow the use of secondary weapons. Initially, carrying more health potions is advisable, and the church in the town provides passwords for continuing the game.

The game features stages set in underwater, desert, jungle, cave, and sky environments. Each stage concludes with a boss battle, and defeating the boss grants the player its unique ability. For example, the Mouse can walk on specific walls or ceilings, the Piranha can move underwater, the Lion can use a sword to attack enemies, and the Eagle can soar through the air.

When all continues are used up, entering "68K" in the leaderboard allows unlimited continues in the next challenge. The game's difficulty is quite high, and skilled players can increase the difficulty further by entering the same name five times in the leaderboard.

In case of a failed challenge, players can press left, right, down, up, select, left when the Game Over screen appears, allowing them to restart from the last successfully completed stage.

To activate sound testing, press I and II simultaneously when the title screen appears, and simultaneously press RUN. Use the arrow keys to change data.

To merge the male and female protagonists, connect the multi-tap joystick adapter, start the game with 2P, press pause, and then continue the game after removing the multi-tap adapter. The two characters will merge into one.