Upgrades are the most important factor for moving forward. When you defeat enemies in battle they will drop start. You can use these stars to upgrade different parts of your ship in the Hanger. Access the Hanger by tapping the bottom right button on the stage select screen.
You should try to unlock the first upgrade for each area before maxing anything out. The high level something is the longer it will take to finish. You can find Cards that will reduce time and cost. There are 8 different skills available. The last 3 (Laser, Energy Shield, Mega Bomb) require you to pay with stars to use them at the beginning of a stage. Start will be better spent on the first 5 in the beginning. The last 3 or more useful for get those hard to obtain medals.
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Health Max Lv4 – Increase for more Health
Try to get this up early as dying is no fun. You start the game with 10 live and when you loose one it takes time for it to recharge. At the start of the game its about 10 minutes to regenerate 1 life, but will increase by 5 minutes per level up of this skill. When you die in a stage you will get your coins and achievements, but you’ll loose any cards found.
Main Cannon Max Lv4 – Increase for more damage and cannons.
This is your main weapon and the cheapest of your guns to increase. This should be raised early for the best benefit. Starting on Stage 4 enemies will have more defense requiring this to be at least level 2 to kill certain enemies.
Wing Cannons Max Lv3 – Increase for more damage.
This will help a ton in making sure you kill everything. Adds a smaller and slower shooting cannon to each wing. Will increase your kill zone dealing more damage to big enemies and increased accuracy for groups.
Magnet Max Lv3 – Increase to strengthen attraction speed and distance.
This will allow stars and power-ups to be attracted to your ship. You should invest in at least the first one as soon as possible. It will increase the amount of stars you pick up. It also make it much easier to grab stars as they come to you and you don’t have to run all over for them.
Missiles Max Lv3 – Increase to raise power and number of missiles.
A must for killing everything on a stage. Helps get that one that got away. Good for dealing damage in situations where your pinned down by enemy fire.
Laser Max Lv3 – High energy laser beam, increase for higher damage.
Cost stars to use and must be selected at the beginning of a stage. Can find for free in crates. To use don’t touch screen during gameplay to bring up menu, then tap the laser. Shoots a laser straight forward for extra damage. Last for a limited time then disappears.
Energy Shield Max Lv3 – Increase to raise amount of damage absorbed and time available.
Cost stars to use and must be selected at the beginning of a stage. Can find for free in crates. To use don’t touch screen during gameplay to bring up menu, then tap the Energy Shield. Creates a protective shield the will absorb incoming damage and collisions. Last for a limited time then disappears.
Mega Bomb Max Lv3 – Destroys all enemies in range. Increase for more range and damage.
Cost stars to use and must be selected at the beginning of a stage. Can find for free in crates. To use don’t touch screen during gameplay to bring up menu, then tap the Mega Bomb.