Like I said above,
Jumpster is a trajectory-based physics game similar to
Angry Birds, but instead of trying to destroy green pigs, you are trying to get your little black ball to his spaceship and collect as many blobs of fuel as you can.
Currently, Jumpster has three worlds to work your way through, each with 20 levels and 60 black blobs to collect. As you collect blobs, you level up your character, but the only thing leveling up seems to get you is access to the later worlds and coins which you can use to buy a myriad of different in-game features, and trust me, Jumpster will take every opportunity to get you to spend your coins.
Jumpster's design seems to have one driving force behind it. If there is a way for the developers to get you to spend the in-game coins, they will provide it, and if you don't have enough coins, you could always put down some real-world money and buy enough coins to cover your needs.
Don't get me wrong, I have no problem with the micro-transaction business model. It works, but I feel it works best, for both the players and the developers, when the option isn't thrown up in your face at every turn. Here, Jumpster gives you the ability to customize the look of your character as well as buy items that lets you unlock worlds and even skip levels if one is too frustrating to get through. In my mind, these are all fine and good uses of the micro-transaction model. You don't have to use it, and there isn't really any change to the overall feel of the game if you do or don't buy into the extras that are available.
Where Jumpster seems to make a fatal flaw, at least in my opinion, is your character's energy bar. Basically, anything you do in the level takes a small chunk out of the albeit long health bar at the top of the screen. Every jump and death you make causes it to shrink just a little bit, and when the bar is depleted, your character is too tired to go on. Mind you, the bar doesn't refill upon completing a level. Nope, basically, you can either wait for your character to recharge, or you can buy one of the items from the shop that will refill its energy bar.
When I first encountered this issue, I was outright baffled by the fact that I had been playing the game for an hour or so and since I had not earned enough in-game coins to buy a "Martian Cocktail" or "Cosmic Cupcake," the only way I could continue playing the game was to either spend real-world money or wait a whopping 12 hours for my bar to be completely refilled. I will say that I could have waited less time and continued the game with it only partially filled, but considering how little gameplay I had gotten into the full bar, this wasn't very encouraging. Since that first encounter though, Vogat has lessened the refill time to four hours, but that is still an awfully long time to wait for such a short gameplay session.