When considering game development, you should be very aware of the importance of testing your game amongst users who have no preconceptions of it whatsoever. When working on any creative project, you should be aware that to maintain creative objectivity, you need to be open to criticism and that testing is just as much part of that as it is a technical necessity. It is all too easy to become used to your game's narrative or mechanics, and often unable to see "the wood for the trees" in terms of how the player will respond to it.
When looking to test your game, try and send test builds to a range of users who can provide test feedback for you with the following variations:
Computer specification: Ensure that you test on a number of differently powered machines, and get feedback on performance
Format: Try sending a build for both Mac and PC where possible
Language: Do your test users all speak the same language as you? Can they tell you if you explain elements...
