Sunday, 18 October 2015

Dare you enter the Vortex

18th October 2015

After the success of Blap 'n Bash. Another new C64 game is in the works. This time, by the way of 'Vortex Crystals' or for short 'V-Tex'. I actually started working on this project back in August 2015. Now this game is going to become a co-op with Alf Yngve, who is using the Sideways Shoot Em Up Construction Kit for designing each level screen. I'll be doing the hard work to capture each screen, and then level pack each screen using the level cruncher method in Exomizer.

So then, what is Vortex Crystals going to be all about?. Well, it is going to be a non-commercial platform game, which I hope to enter for this year's 16KB Cartridge Game Compo, run by RGCD. Each level is a static screen, which will contain mechanical aliens, such as walkers and floaters.

You have been assigned to enter a the Vortex Complex, in which you are required to pick up all of the crystals. In order to pick up the crystals, the use of UP via the joystick, will need to be read. After all of the crystals have been picked up. A key card will need to be picked up to open the exit. Unfortunately you won't be all alone in each complex. A series of aliens will be guarding the premises, by moving up/down or back and forth. The aliens can be shot dead with a number of hits- if you have enough ammo. If all crystals have been taken from each room of the complex, an alien will need to be killed, in order to retain a pass to open the security doors.

At the moment the aliens are in 3 different forms, which are as follows:

Rotora - Only moves in the air

Zorbot - A satelite robot which will move on ground

Walker - These mech aliens move on ground via bionic legs.

After destroying an alien,  after a short period of time, it will re-spawn.

Capturing the levels

I first started on the level design to build a simple template for Alf Yngve to tidy up and design more. Different background objects should use different a form of behavior. Most of it of course is static background/decoration, but there are some obstacle chars set in the background. We chosen the Shoot Em Up Construction Kit for designing the each level. Alf constructed 3 test levels. Graphics were much more improved and the obstacles looked even better. Obstacles planned for the game are as follows:

Upper platform - Player can walk or jump from this
Lower platform - If player is jumping and hits this , it should fall
Ladder - Jump should be disabled, when the player is climbing up/down a ladder
Spikes - If the player hits this, the spikes should kill it.
Conveyor belt - These will move either left or right, and move the player along
Crystals - Stored in a storage base on the wall, these should disappear after the player touches them when jumping up to grab them.

The actual game is planned to NOT be a SEUCK creation. So I used VICE M/C monitor to capture the screen and colour RAM data, and transferred it to another screen area, and then I saved each capture of the screen separately. The original background charset also got saved from SEUCK for use in the game code as well. Once I finished capturing 3 screens. I level packed each screen and colour data, using Exomizer V2.09. Then I got into programming the main game framework and composing the music.

Composing the Music

Composing the music was quite easy - and the most fun task. Last week I loaded up an old tune, in Goat Tracker V2.7 which I started to compose. It was originally called "Gilmore", as the tune was inspired by Gizmo's tunes from the Zzeppelin Games era (Psi Droid, Ninja Commando, you name it). I worked quite hard on composing music using a similar style for the game. However, I wanted to try something more uptempo and quite bassy, with drums, but not trance (You'll be pleased to hear about). Then I composed some jingles. The tunes turned out quite well, and Alf Yngve seems to like the in game music, which I did for the game.

Coding the game

Programming the main part of this game was quite simple. I created routines which can move aliens about, and also the player when controlled with Joystick port 2. However I came across a snag in the game's code. I needed to create a logic for a different  effect on the player. If the player was in air and not jumping, I had to set the logic where the player will fall. If on a platform, but not on a ladder. The player can jump. However when the player reaches the top of the ladder. It cannot advance on to the next platform. I did a little experiment to search for a solution to this problem. If that wasn't bad, then when the player descends down the ladder, it stops and ducks down at the wrong platform char.   The  good news is that I found a solution to this problem.

I froze the framework with Action Replay and played around with the screen editor. It seems that an extra char above the ladder solves the problem of not being able to walk on to a platform. Also removal of the 3 ladder chars in the bottom row also stopped the player from going to the wrong chars at the very bottom of the platform. So now each block which Alf created, will need to be re-designed adding 1 row of chars for the top of the ladder, and the bottom row with a fake ladder, or something else. So that the code can allow the player sprite walk across the platform.

The deadline for the game entry is 31st January, which gives me about 3 months to finish this game. Although I have a very busy 2 months real life ahead of me. I feel pretty confident to get this project finished in time for the compo deadline. More about my progress of this game in the near future.


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