About The Gameplay
Go to areas of the planet Hera affected by the invasion and destroy the leaders of the alien forces, along with any other resistance met. You will have to fight in the air and on the ground. If your goal is uncertain, try to locate key objectives using the map mode (ground stages only).
Your repeater rifle can fire without limit. You can hold down the chosen key to fire continuously at a rate of 10 shots per second. Your special weapons (found throughout the planet) have limited ammunition specific to each weapon, but ammunition pickups will affect all of them at once. You can equip three special weapons simultaneously.
When you dodge, you move quickly, but briefly in a given direction. You are invulnerable to damage for a fraction of a second while doing so. Dodge Tools are equipment meant to enhance your dodge, with specific additional effects based on each tool.
Seraphine and her microjet apparatus are protected by an ablative kinetic barrier, also known as a "shield". When your shield energy (represented by a number and a blue bar) is exhausted, you will be able to use a piece of emergency equipment known as a Crisis Trigger, which automatically grants a special buff or performs a task the moment your shields hit zero. Some of these require that you fill a "Crisis Gauge", by picking up items. As you acquire points, your shield strength potential gradually increases.
As long as you have any shield strength remaining, you can survive whatever the invaders throw at you. However, if you take one more hit after this resource fails you, the game is over.
When defeated, you will have the option to continue, return to the title, or exit outright. Continuing will bring you to the start of the last scene you entered when you were defeated, retain your score, and fully recover your shields and ammunition.
Some enemies drop items (shields, ammo) when defeated. You can pick these up by touching them either on the ground or in the air. Ammo pickups also restore a reduced amount of shield energy compared to the dedicated shield pickups.
Do not be afraid to go off the main path in order to find extra equipment, talk to characters and learn new information, and increase your maximum shield strength via gaining points in combat.
Air Stages

Using the microjet, Seraphine will fly in one direction from one area to another, clearing the airspace to a specific destination. At the end of some routes, there will be a boss that she must clear in order to land.
Ground Stages

On the ground, Seraphine will access her map, battle land-bound enemies, meet friendly characters, enter buildings and acquire equipment. Many of the major invaders are in specific areas she must land in order to reach.
Pause Menu

The Pause Menu contains the following:
Acquired weapons
Acquired crisis triggers
Acquired dodge tools
Contextual information for each piece of equipment
Shield strength/maximum
Repeater level
Score
Score requirement for the next shield strength maximum upgrade (in increments of 100 units)
Map Menu

The map menu contains the following:
A zoomed out representation of the current scene.
Markers representing required and optional objectives.
Detailed objective information.
Your current X and Y position in the current scene.
If zoomed further toward a continent or the planet at large, you will also have the option to quickly travel back to a ground scene you previously entered.