Space Invaders (for ZX Spectrum/TS2068/TC2068) by SplinterGU

Version 1.0
– Initial Version
Version 1.1
– Game syncronized at 50hz
– Fix saucer/UFO speed
– Fix player shot speed
– Fix alien shot speed normal, and when less of 9 aliens (bit faster)
– Smooth alien shot animation
– Add sounds BeepFX based for “BEEPER” Sound (original BeepFX player by Shiru http://shiru.untergrund.net)
– Add AY Sounds (Fuller Box, Sinclair 128k)
– AY Sounds from and made with AYFXEdit ( https://zx.remysharp.com/audio/)
– Autodetect Sound (Beeper, FullerBox, Sinclair 128k)
– If only 1 alien left, move a bit faster from left to right, as original
– Fix no delete right arrow in configure menu when players control reach the limit
Version 1.2
– Add ZX81 Version (require zxpand or rampack 32k)
– Now aliens move one at a time
– Fix aliens score
– [ZX81] wrx support
– [ZX81] chroma-81
– [ZX81] zxpand joystick support
Version 1.3
– Fix gameplay 2 players
– Re-code lot of functions to ASM
– General better speed
– [ZX81] AY-Sound + Full Chroma-81 Support
– [ZX81] Full version, look as ZX-Spectrum version
– Fix other minors bugs
Version 1.3+
– Reduce alien step sound volume to 50%
Version 1.4
– TS2068/TC2068 Support
– Sprite rutines optimization
– Fix sound detection
Version 1.4.1
– TS2068/TC2068 Joystick Support
Source Code:  https://github.com/SplinterGU/SInvaders