I've actually been going back and fourth with GOG staff on this one.
Aside from the framerate being about 48 FPS on a frame-skip aligned to 60 FPS (leading to it being very cutty and laggy) I can't seem to get past the first boss without it crashing, if I'm even lucky enough to get that far... I've already tried reinstalling, with and without the patch, as well as disabiling various things, cleanbooting, reinstalling directX... On the bright side, at least there's now a moneyback garentee... Never thought I'd have to use it either :c

First, I'm not likely capable of helping you. Second, those screenshots are worthless. You need to click on click here for the specific error. Yes, sometime it's as generic as what you posted, but occasionally it's useful.

Have you tried rolling back to earlier graphic and/or sound drivers? Be sure to include your full hardware specs & OS.

I notice a frame rate reduction from the original games, but it's not choppy as some would find it. Although it does affect the proper display of the shadows of the objects on the screen it does not annoy me much. I find it runs smooth but if perfection is what you are looking for , Dot Emu lacks in it , just take a look at their Irem Arcade Hits they released, they still can't fix certain issues due to licensing snafus and what have you, the emulation is half (cant print the word in here ) but you get the picture.

Raiden Legacy is much improved emulation over their attempt at arcade perfectness in Irem Arcade Hits, but Mame and other emulators can still do it better.

"they still can't fix certain issues due to licensing snafus"

With the IREM pack? It's not a licensing issue. They just quit working on patching it because it wasn't profitable, apparently. There was even a second patch planned, with a release date, and it... just evaporated?

As far as I can tell, their internally developed emulator is just busted. Licensing issues might've blocked the JP version of Undercover Cops geting added, but that wouldn't impact fix their sound emulation.

I've ended up adding support to MAME for the Dotemu roms so that I can actually *play* them right.

Will you be making this available for others at some point?

More info please.

Is there any chance you could link us to this fabled MAME build? I would love to play Raiden Legacy without the crazy lag that isn't present when you emulate it in MAME.

How? Please respond.

But MAME can't run the ROMs.

https://www.dropbox.com/s/muflen54ccybaxj/Dotemu_Mame.zip

This is for the Dotemu roms. Just to note, this /only/ works with the legally-purchased rom sets included with Dotemu's IREM pack, and if you want those, you're going to need to buy them from Dotemu, GMG, or Desura. You'll need to move some files around to get it working -- I think the rom sets are within a zip file containg, uh, stuff for the UI? Also I never added in Kung Fu or Vigilante because they were weird and I was mostly interested in the shmups anyway.

I never actually got the stuff from Raiden Legacy working. Basically, Dotemu's IREM roms were generally pretty close to what MAME already uses, so adding support for them wasn't hard -- it's basically just making some files that define what's in the zip file and where to stick it in RAM.

The Raiden Legacy roms from Dotemu, on the other hand, are weird and I think they MAY have been modified to work with Dotemu's loader thingy. The size's are also different -- MAME as it stands is expecting some about 22 megs in size for Raiden Fighters, but the rom from Dotemu is 36 megs large.

Honestly I might even hazard a guess that the issues some people have with RL aren't with the emulator Dotemu used but are a result of the roms being weird.

--- update ---

For what it's worth, here's what I've found from looking at the MAME driver code for Raiden Fighters:

rdft_i386.bin as-is corresponds exactly to what gd_1.211, gd_1.212, gd_1.210, and gd_1.49 look like once loaded into memory.

rdft_soundrom.bin as-is corresponds exactly to what gd_pcm.217, some padding, and then gd_8.216 look like once loaded into memory.

Dropping these into an MAME driver for Raiden Fighters would be trivial.

The problem's entirely the graphics ROMs.

I have no idea what rdft_ds2404.bin, rdft_eeprom.bin, rdft_flash0.bin, or rdft_flash1.bin are for from Dotemu's pack -- the original MAME drivers for Raiden Fighters don't appear to use anything like these. It sounds like a DS2404 is some sort of chip for time related things, and EEPROM is used to save data. Maybe they were used for tracking high scores and playtime on the original board?