Well, this is where the fun begins :). I worked on a 1 screen test level (To get the tiles working) and imported the test level library from the Multi Screen Construction Kit. Then I started working on some more programming aspects to the game engine.
There were two new tiles for the game. One which was a temporary shield, and the other which was the switch. I loaded up VICE and the game's graphics work files to work out which character indicated the shield, the switch (on) and also the switch (off). Then I added more to the sprite/background collision register routine. Some of the routines check for the value of the character. If it was the shield tile then to test this was working I added INC $D020 to increment the border colour (test). Then I did exactly the same thing for the panic switch, but DEC $D020 to decrement the border colour (test 2) instead. I also got the tiles to change. The shield tile turns into a standard tile (Shield disappears). The switch on tile turns into the switch off tile. I assembled and executed the new code and tested the test level. The increment/decrement of the border worked. Now it was time to add some more routines to make the code work how it should have.
Some more variables and timers were added for the shield routine. The idea was to create a timer that will give the player a temporary invincibility mode. I also created a table which should flash the player (silver/grey flash scheme). A routine to time the shield counter was also added. I also created a routine to check whether the timer equals 0, indicating that the shield has been disabled. Otherwise the sprite/sprite collision would be bypassed. After I assembled and tested the routine. I had the player flashing for some time (after collecting the shield) which was perfect. Especially for the harder stages of the game, where there will be tiles with panic buttons surrounding the pods.
Now the invincibility mode was sorted out. It was time to add some interesting features into the panic switch routine. I decided to make it look as if the alarms were going off - and the seekers speed up during a short period of time as well. This was to make game play more frustrating and fun. Like with the shield routine, I created a timer and also two colour tables for the background multicolour. Yes that's right, the background multi colours flash on panic mode. The effect turned out nicely, and also the background restores to its normal colours after the panic alarm's switched off (automatically). :)
20th May 2012 More level designs ... and the master of disaster strikes ...
I have been doing some more levels using Multi Screen Construction Kit today, and have 25 working levels done so far, but the bad news is that after level 26 was stored to the MSCK library and I wanted to view all of the levels through MSCK, the program crashed (CPU JAM at $C107). It was very complicated to look at the code. So I'm not sure whether or not it will be possible for me to recover the level. If it is not recoverable, I will have to redesign the same levels using a different utility (I might try Delight by Color7 productions), but it will be a longer process in designing all of my levels (Using 2x2 tiles). Here's a snapshot of what Level 26 could have looked like (if I'm accurate enough).