Which low budget video camera would be appropriate for making travel/advenutre short films?
For your budget and situation, GoPro is probably the best bet as it is exceptionally light and a good value for the money.  It doesn't have a variable length lens, so it can be a little limiting in shot composition, but you won't get the same video quality, weight and durability in any other camera for the same price.  That's why they are the market leader in that segment.  

Most other cameras that are that cheap sacrifice either quality and durability or size for more versatility and consumer friendly features, but at that low of a price point, there isn't enough budget for making the device to keep much of any quality with any kind of versatility.  (As an example, an optical zoom lens of decent quality would probably take 1/4 to 1/3 of the budget of a camera in the price range you are looking for.  That doesn't leave much for sensor and processing electronics.)