"We ran into an unexpected issue at the last minute. The issue only seems to affect a small portion of players, but we're not comfortable shipping the game until we've resolved it," Justin Korthof of Robot told Joystiq. "We know it's a nuisance for players who were excited to start playing yesterday, but it's important to us that Hero Academy is at its best when it's released."
Steam now lists the game with an August 16 release date, but Korthof tells us that's a placeholder.
"While it could take that long to release, we're optimistic that it will be out sooner than that," he continued. "We want to release the highest quality game possible, and we're working hard to get this issue resolved quickly. We're hoping to have more info about an updated release date later today or early tomorrow, and we'll continue to keep people updated through our Twitter feed and Facebook page."