From the Appscope listing:
Global Defense is a Massive Multiplayer Online space defender game. Start a game as single player and destroy the asteroids approaching the planet.
The URL to tap on or type in is globaldefense.club .
Of course, you can turn this into an 'app' yourself with PAWA or just pin it 'as is' on your Start screen. It's up to you. If you're confused by the different PWA options then check out my feature here.
Here's Global Defense PWA in action:
Retro wire frame graphics are a nice touch; (right) here's your starting point and you should pay attention to the instruction - you have to rotate your phone to aim, where you tap on the screen (to fire) is irrelevant.
What's odd - and I wonder whether it's a technical limitation - is that your little spaceship/gun doesn't rotate with your phone orientation/aim. But get past that - and you will - and this is a nicely pitched casual game which flows quickly and gets hard quickly - how long can you last until 'Game over'?