Hero Core - Official game guide|
Introduction - Basics - Enemies - Bosses - Trivia
Normal - Hard - Annihilation - Boss Rush - Hero Forever
Health, levels and abilities
You start the game with 10 hit points, and every time you defeat a boss, your level and maximum hit points increase by 1. You'll also get an upgrade, usually to either your Blaster, Blade or Suit. Here's what they do:
Zones, Generators and bosses
On Normal and Hard difficulties, your goal is to defeat Tetron, who is located at the very center of the asteroid. The Core zone is well guarded, but you can pass through it to enter other zones very early. You can destroy the Generator in the Core zone and face Tetron without any upgrades, but it's very tough - it's easier to face some other bosses to grow stronger first. If you defeat all of them, Tetron should not be a problem.
Saving and warping
You can hold both Fire buttons at any time to warp to any savepoint you have seen. Even if you run out of hit points, Hero is safely teleported to the last savepoint, and no progress is lost. Warping is the fastest way of backtracking through the asteroid.
Press Spacebar to activate autofire, which makes Hero fire 8 times per second. You can still fly around and aim left or right as usual. However, you can only have six bullets on-screen at once, so try not to miss the enemies or it'll take a while for your next bullets to be fired.
Firing both ways
Tap both Fire buttons at once to fire left and right simultaneously. This comes in handy for the Rock Smasher boss in particular.
Use the Blade for higher damage
The Blade can be charged while it's impossible for you to hit your target, then released once you get close for high instant damage. When it's possible to move in with a charged Blade, release it and then start firing regular shots immediately afterwards, this will give a higher damage per second output compared to just using either the Blade or Blaster once you move directly in front of the target. When facing enemies that fire bullets, an initial Blade attack will also push those bullets away on top of dealing damage.