UPDATE: Version 1.1:

faster ship
constant enemy spawns (no delays)
muzzle flash effect and better explosions
other gameplay tweaks

STORY: Welcome, Pilot 8. You are our top choice for this mission. I mean, 8th choice. Nothing suspicious at all happened to the other 7 pilots that came before you. They... uh... retired. Anyway, here is your comprehensive battle training: use the arrows to move, press [Z] to shoot. End of comprehensive training. Off to war you go. Good luck, Pilot 8.... Ok, that pilot is hopeless, let's start training Pilot 9. Oh, what? It's still on? How do I turn this off <click>
This is a simple space shooter.

18 levels across 6 worlds (Flood City, Oasis, Marshes, Coast, Canals, Fortress)
Different weapons and powerups (shield, weapons, etc).
Collect chips dropped by enemies to upgrade your ship. 14 upgrades available:

extra speed
rapid fire (3 levels)
ammo capacity (3 levels)
shield (3 levels)
starting laser
powerup frequency

World map

Tech aspects:

Dynamic lighting (via framebuffer post-processing).
Screen-space reflection (water effect, lightning, etc).
Particle effects, rain, etc.