Improving Atari ST Uridium

[Petari]

ST version of Uridium is known as slow and not well playable. Usually people blaming lack of HW scroll support for that. But scrolling self is actually not that bad. What is very bad is slow ship control - it accelerates poorly, turning 180 degrees takes too much time, so hard to play, if possible at all to finish some levels.
I went in improving it. Better scrolling is done by help of blitter. Faster controls needed lot of tracing, code examining.

2 test versions available.
One is for STE, Mega STE. Mega ST, or any ST with blitter. 512KB RAM is enough. Can run from floppy or hard drive.
Selectable start level, so you can try all them quickly.

Other version is with original scroll, just controls are improved - so any ST, STE ... 512K RAM is enough.
Please test it as much can. Feedback is welcome.

This is not final version - I need yet to update sprite draw code in blitter version - because now using whole screen width.
Your Manta performs a 90 degree roll if you press and hold fire whilst moving up or down. This will enable you to manoeuvre through restricted spaces.
Level maps included.

http://atari.8bitchip.info/URIDT1.ZIP

https://youtu.be/EmzUAJkKgJM - Blitter v. on YouTube.
https://youtu.be/HA6RaeGAq1k - Original scroll v. on YT.