Changes
/* Shame */
This game is not really good indeed.
The reason is that it is a shamefull [[Speccy Port]].
Just look at the Spectrum version to see what i mean.
But sprites and animated stuffs are some sort of 1bpp Spectrum graphics (with attributes) transferred into Mode0... probably with a CPU intensive process as the emulation (WinApe, option "find graphics"...) can't enable to find the graphics... (no pre-coded graphix). As a result we can seem ugly attributes and the Wide pixels of Mode0 can't do justice to the design of the varied aliens (on Speccy they manage to look quite good actually)
The use of the Hard-wired sprites is obvious : the target/cross-hair... but sadly the bullets use most of the rest of the HardSprites slots while less or different method could have been usedto let some extra Hardsprites slots for extra special effects.
The playfield also use some raster which are quite similar to the Arcade... but sadly this simply displays even more the unmasked tiles/characters from the sprites. could have been better provided the sprites were properly 4bpp coded as the "raster ink" would be used as a "sort of a mask".
== Use of Plus Features ==
* Plus palette is used throughout (colour fading, extra colours throughout)
* Plus raster line interrupts are used (for changing modes for example)
* Plus screen split is used.
* Plus hardware scrolling is not used.
* Plus DMA sound is not used.
* Plus hardware sprites are used. (used for the title page logo, your aiming reticule, bullets, and the Scanner/Radar at bottom of screen HUD).
The hardware sprites use ink cycling. The Visor uses 2 sprites with some colour cycling and those sprites may change if you change the selected weapon , bullets use 2 sprites slots per frames (6 frames, so 12 slots) and Radar uses 2 Sprites with colour cycles too. Those sprites are all magnified into pseudo Mode0 sized pixels (X=4 and Y=1). To use sprite for the aiming reticule is an easy way to get masked and smooth movement while the game is non masked and attribute movement based.
*'''Others :'''
*'''Mode change :''' the texts during Menu page or cinematics, and the upper HUD (top of the screen) are in Mode2 (1bpp) while the rest is in mode0 (4bpp). Despite being Mode2, the letters (characters) used 16 pixels and could have been done in mode1. This part seem to slightly bug on emulator.
**multiloadings are used as the game must be quite heavy on memory requirements. on cartridge, this game properly done would have needed 256K or even 512K ROM cartridge. As a result only the 6128 config can play this (with no ROM).
** The '''cinematic screens''' look a lot like the C64 version ones but more coloured and with a bit less attributes limitation remains.
** The "find graphics" option on WinApe enables to find the graphics for the 2nd player's HUD... but this multiplayer feature is simply disabled, so just those graphics just became a waste of RAM.
== Links ==
