Vertical Shmup - Part 1 - Introduction

A couple of people have asked for some tutorials on creating a Vertical Shoot-em up with MPAGD, something along the lines of Imagine's classic, Arcadia.

This sounded like a good challenge....but one I might come to regret...but let's give it a go.

First, we need to be mindful of a few limitations of MPAGD for this type of game.

MPAGD has a command, LASER which will fire laser beams (basically a plot of pixels), think JETPAC, and collision between a laser beam and sprite can be detected with IF COLLISION BULLET.

Unfortunately LASER only accepts LEFT and RIGHT as arguments, so beams can only be fired horizontally.

Might not be useful for our game, as we'll be shooting upward. Therefore we are going to need to use sprites for our bullets...

Which leads us on to our next issue, MPAGD will, as standard, only allow 12 sprites on screen at any one time, We'll need to account for our bullets - this will inevitably impact the rate of fire for our player spaceship (and also for any enemies that drop bombs!

Aside from that, I think we've got all the other tools we'll need for a half decent vertical shmup.