This is a low-optimization TAS I made of just the first level. Here's an encode of the movie: https://youtu.be/rMD_Gyj3Eeg
The makes use of a TAS-only route, as taking the lower path in the second section requires having perfect shot accuracy to have enough points for the required bronze rank. In addition, this also makes use of strafe walking, which allows you to move significantly faster than just walking forwards.
This can be optimized significantly. The most significant time loss was from grabbing the suitcase before dispatching the enemies in the room it's in, but I also didn't spend any significant time optimizing the movement, so I'm sure there's time to be saved there. There's also possible manipulations that would probably improve the time, including lag manipulation (not just lag reduction, but also creating intentional lag) and (from what I've heard) truck manipulation in the first section.
Also, I've noticed this game is really sensitive to emulator accuracy. I recorded this with BizHawk 2.8, and it already desyncs running in BizHawk 2.9.1. If I do get around to making a full-game TAS (which I'm interested in making), deciding on a fixed version of BizHawk will probably be necessary.