Core Design's original concept for the game had been to make it more of an action title rather than an adventure one, initially being envisioned as an isometric-view role-playing action role-playing game in the style of Core's own 1991 "Heimdall", before the project has evolved into a more classic, completely 2D, side-scrolling adventure game (yet still sometimes being described as a role-playing game). It was proposed as "an adventure for people who hadn't played that kind of game before." The protagonist's effective invincibility was a late demand by the executive producer Jeremy Heath-Smith. The game's co-designer and the Amiga version's chief programmer Rob Toone said that their idea was to make these parts of the game "interesting without being difficult." Co-designer and the PC version programmer Ian Sabine stated that the lack of text "speeds up gameplay". Regarding the decision to keep the onscreen text to a minimum, Toone said that "too much reading can slow the game or kill it, like "The Adventures of Willy Beamish"," with the main artist Rolf Mohr adding that "hopefully, a picture will say a thousand words and make this system easy to use." According to Toone, "Lucasfilm gets most of its humour out of its text, whereas we hopefully get ours from comical animations and daft happenings." Core's Richard Barclay described it as "a huge icon-driven epic of the Sierra On-Line/Lucasfilm ilk." Mohr named Sierra's "King's Quest" and "Space Quest" series as his big influences.