Sea of Dreamland is a relatively obscure title for the NES. The lack of regional specification (Unl, meaning Unlicensed) suggests it may be a homebrew game or an unlicensed release not officially sanctioned by Nintendo. Gameplay details are largely unknown, as information regarding this title is scarce. It's likely a side-scrolling adventure or platformer, given the common game types for unlicensed NES titles. The absence of readily available information on developers or publishers makes researching its history challenging. Without official releases or documentation, tracing its origin and overall impact remains difficult.  Due to its unlicensed status, it was not part of Nintendo's official marketing or sales records. 

Sea of Dreamland (Unl)

SD Hero Soukessen - Taose! Aku no Gundan (Japan)