Windows 7: Shadow Man acts weird

Shadow Man was released for PC by Acclaim in 1999. Initially I'd found no problems running under Windows 7 but after a near-complete playthrough...

* certain animated textures and elements animate at a very fast speed
* slopes and hills seem to behave like ice in that the player slides down them when standing, waking up them can be quite a chore
* enemies and such often get stuck on the environment or will wriggle around in place, jittering
* cutscenes go dark as if the light source isn't projecting
* instances of climbing up a ledge sometimes cause the player to fall through the floor
* the zombies in the Gardelle Jail level are unkillable. This makes the level nearly impossible



This might sound like a buggy game but these problems did not happen when running the game under Windows XP 32 bit. My main theory is that the video card isn't handling the game properly which could account for the sliding, jittering monsters and fast animations. I'm also using an Xbox controller with XBCD, this could account for the sliding on slopes due to the more sensitive nature of the analog stick. That doesn't explain the unkillable monsters though. I've found the game also supports 1600 x 900 resolution but it may not fully support, as the game is older than it's usage. It could be a combination of things. Does anyone have any ideas?