Currently we have no plans to release an English dub for the game.
Apologies if you felt misled by the original trailer as to what content would actually appear in the game: we hope that the game's lack of English voice acting isn't a deal-breaker, but if it is, please feel free to request a refund from Steam. (Steam should be able to issue a refund for the game as long as you request it within 14 days of having purchased the game and have logged a playtime of less than 2 hours.)