Okay, with regards to sound in Lemmings Revolution, I have some good news. I think I've figured out the problem (or one of the problems anyway) some people might have with sound on Win7 (and probably Vista), and it can be fixed yourself without having to patch or change the program in any way!
(Please refer to attached screenshots.)
Step 1: find the sound icon at bottom right of your screen (circled
orange in screenshot). Click on icon with your
right mouse button (ie. "right-click"), then select "Playback Devices" from the popup menu.
Step 2: a popup window appears, showing a list of all "devices" you can play audio to on your computer. You might think your computer only has one output device you can play sounds to, but apparently on Vista and Win7, a lot of computers might have this "high-definition audio device" support that provides two or more outputs for sound, like my screenshot.
The irony however is that other than the (presumably working) audio device you are currently using (shown with green checkmark in the popup), the other ones listed probably won't work for you. For example, in my screenshot, the other one listed as "Digital Audio (S/PDIF)", I have never gotten sound to work playing out of that device. (I later looked up Wikipedia and S/PDIF seems to be some fancy connector to connect to Hi-Fi equipment, so maybe I just don't have such a fancy setup to take advantage.)
Now the problem turns out to be that, rather than using the working device that the system has selected for playback (ie. the one with green checkmark in the popup), Lemmings Revolution apparently has its own way of picking which audio device to use to play sound, and unfortunately its choice is often the wrong one (eg. the S/PDIF on my computer which I can't get sound out of). This turns out to be the reason for no sound.
The solution? Just disable all the other audio devices on the computer that you aren't using anyway. Thus the final step.
Step 3: For each device
other than the working one with green checkmark, right-click on the device entry. A popup menu appears, select "Disable". Just as depicted in screenshot.
The device entry should either go away in the list, or become grayed out with accompanying "disabled" in the text next to the device icon. Repeat this until you are left with just the one device with the green checkmark (ie. the one currently in use that actually plays sound). Now click OK to dismiss the popup.
[note: if you make a mistake, or somehow need to re-enable those secondary devices at a later time, you can right-click on a blank space in the list and select menu option "show disabled devices", and then use the right-click menu to re-enable any device you previously disabled. The right-click menu also lets you specify which device to use by default for playback (ie. where the green checkmark goes), in case you messed that up.]
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After I did that on my computer (leaving only the "Speakers" device enabled), sound now works on Lemmings Revolution! Hurray!
[disclaimer: obviously your mileage may vary, but no harm trying at least!]
Of course the graphics are still messed up. I'm afraid that won't have any easy solutions.