The aim of the game is pretty simple (collect the treasures stolen by the denizens of this hostile world), as are the controls - a simple side-scrolling shooter, in the main. Run, jump, shoot, dodge, collect, and above all, explore! Most of the stolen treasures you'll find will bear with them some tangible (and necessary) benefit. If you reach a place it seems like you can't pass, or find a monster it seems you can't kill, it almost certainly means you just need to look for whatever as-yet-unacquired item it is that will allow you to conquer the situation and move on.
Also bear in mind that the world around you doesn't operate the exact same way all the way through - you'll find you're suddenly jumping much higher during your visit to the planet's moon, for example. Down to one life? Don't panic - too much; this game is another one that subscribes to the "a life means an extra chance, not the one everyone has to begin with" school of thought.
It's a difficult game, as I recall; between the stiff movement, potentially crowded spaces, devious (but not brilliant, of course) enemy tactics, and the pitiless (and common) chasms of instant death, it pulls no punches. Then again, it's also been a long time since I've played. The surroundings are jolly and
interesting, and there is an unhidden humor to the whole thing. It does a good job of surprising you in its answers to the question of, "Where am I going to end up next?"
In summary, you can, if you wish, think of this one as a "collector's item" This is a "novelty game" as good as any, and sure to be well-worth the KILOBYTES it will demand of your hard drive.