Full of Stars is an "runner"-type game that's similar to Temple Run in that - Hey, wait, I know, I know, but listen, it's different, trust me on this!
So, unlike Temple Run, Subway Surfers, or all 1.5 million endless-runner-type games out there for mobile, Full of Stars has a story with more meat than "something's chasing you so you'd better run fast" and persistent elements that are more than "you collect enough of this thing you can make your character a different color".
See, the game has two parts - one where you, well, fly through a realm known as the rift, which allows people to travel across several thousand light years' worth of space travel in just a few minutes, and two, where you make choices on what to do at your destinations or what happens when the ship crashes.
The Rift lets you travel quickly, but it's also quite dangerous. If you crash into an asteroid during the tutorial/starting segments of the "Cargo Pilot" story, the first of two stories currently available, there's a very real risk your journey might end right there. See, whenever you crash in the first part of the game, usually an event happens that forces you to choose between a certain number of things, but we'll get to that in the bottom half.
The second part of the game involves events - both events happening after the crash, and events happening once you reach your destinations. Here, you'll interact with the four resources you'll have to manage.
Crew: The number of people currently on the ship, including yourself. You usually get a few events that add crew members at the very start of the game, and might be able to find more along your way if you're lucky. Nearly all events that happen after you crash will force you to make a decision or risk losing crew members. If the number of Crew members drops to zero, well, you are probably dead and will have to start a new journey.
Idium: Some kind of mineral/currency. Can be used in either events or in upgrading your ship's Laser, Bomb, Overdrive, and After-Crash Stabilizer. These are the equivalent of coins in that they're really easy to find in the rift and it takes a lot of Idium to upgrade an item/be used during an event.
Idium Crystals: A more valuable form of Idium. Can be used to provide a second chance when you crash, usable in events, used to upgrade your Crew Quarters, or to break down into Idium. These are basically the premium currency - they will appear somewhat rarely in the Rift, may be provided by some events, but can also be purchased.
Leadership Points: This isn't really a tangible thing. Maybe it's confidence, morale, or omsething else entirely. Whatever it is, can be used in events. These are gained by either certain choices in events, or by completing challenges - objectives that you can fulfill during a run to fill up the bar.
Laser: You can either equip this, or the bomb. Charges up over time. Once charged, tap with two fingers or swipe down to fire a laser for several seconds that will destroy asteroids in front of your ship, leaving behind idium you can pick up. Upgrades will let you charge the weapon faster, store more charges to use in a row, drain idium from planets and moons (which cannot be destroyed by the laser), and act as a magnet.
Bomb: You can either requip this, or the laser. Charges up over time. Once charged, tap with two fingers or swipe down to activate a bomb that will destroy all asteroids in certain radius. No idium is left behind by this, however. Upgrades will let you charge the weapon faster, store more charges to use in a row, and destroy planets, moons, and alien structures.
Overdrive: You'll always have this equipped. Charges up as you collect idium. Once charged, tap with three fingers or swipe up to enter Overdrive, where you'll skip a head a certain distance. Upgrades will let you travel farther distances in Overdrive, add more slots to use overdrives one after the other (or all at once), and let Overdrive charge up over time.
After-Crash Stabilizer: You'll always have this equipped, too. After you crash, you'll have the option to either immediately end your run (and thus jump to the after-crash event) or spend idium crystals to recover from the crash. As you upgrade this, the number of crashes you can recover from during one run will increase from three to twelve.
Crew Quarters: Dictates how many crew members you'll be able to carry at once. If you have more crew members than you can hold, you'll run into events that'll cause you to lose more crew until you're within capacity again. Also, you'll lose crew members every time you perform an after-crash recovery.
An event might go something like this (I am not quoting from the game, mind, so it'll probably look different when you come across it):
A group of people is getting pissed because there's not enough food to go around. You can either:
(Chance of success/failure) Call for backup
(Leadership Points) Share your food
(Idium Crystals) Set up a food plant
I'd tell you what options would be best in what situations, but that might be spoilers - in any case, you'll have to manage the currencies as you travel from spot to spot to save humanity.
It's worth a try. Advertisements only appear when you're recharging your core (energy system, you can perform 3 runs in a row, then wait, watch a video, pay idium, or purchase an unlimited core in-app purchase), and all in-app purchases are completely optional.