Raiden is in development for the Atari STe by Scott Clifford, he of Frogger fame. Scott got the idea after seeing the Falcon version and figured there was no reason why the Atari STe couldn't handle this. I agree and simply had to contact him. We had a good chat this morning, such a nice fella and he told me the specs he hopes to use: hardware scrolling, DMA audio, Blitter sprites, chip sound effects, and perhaps even support for the analogue controllers.
I cannot wait to play Raiden so watch this space for updates!! :-)