So this is very nitpicky (hence my profile name), and perhaps it is intentionally this way, and also I am a physicist without radio astronomy experience, but here it goes anyway. I also tried making this somewhat pedagogical for anyone that is interested in the science.
The tl;dr is: unless there is a story reason otherwise (or I am misinterpreting what these settings are), the Filter offset on the Frequency Filter should have the range and units be something like 100-1000 MHz, and polarization is probably fine, but could be "fixed" with an ellipticity setting. And if you could make this game like that scene in Contact where the main character gets the signal, that would be crazy awesome. All of this is out the window if there is a story reason for the download console setup.
There are lots of ways to put a unit on a frequency: deg/s, rad/s, Hz (Hertz, periods/s or repetitions/s). It's a change in angle over time, or the number of instances of an event over time. For instance, if you roll a wheel so that it makes five rotations every second, it would have a rotational frequency of 5 per second, or 5 Hz.
An electromagnetic (EM) wave constitutes an oscillating electric field and magnetic field -- but let's just focus on the electric field. You can think of an electric field measured at some point being an arrow of some length and pointing in some direction. A bigger arrow indicates a larger field strength, and the arrow's direction indicates the field's direction (where it would push a positively charged particle, like a proton or a positron). For linearly polarized EM waves, the field is pointing in one direction, then shrinks and shrinks until it is nothing, and then starts growing in the opposite direction until it reaches the same magnitude it was before, and then it starts shrinks again and the process continues. What you're left with is a wave -- the electric field oscillates "sinusoidally." When characterizing a wave like this, you might count the number of times its underlying electric field oscillates and goes back to its original direction and length in a second, and call that its frequency. For radio astronomy, this is exactly the case! The frequencies involved are in the 10's of MHz (megahertz, 1 million oscillations per second) to several GHz (gigahertz, 1 billion per second). This is mostly just due to how EM waves interact with our atmosphere -- these frequencies are largely unperturbed.
If I were to change the units on the Frequency Filter console screen, I'd probably just make the range go from 100 MHz to 1000 MHz = 1 GHz. That is well within the range of what waves can be seen through the Earth's atmosphere. See this chart from Wikipedia -- and the frequency can be calculated by dividing the speed of light by the wavelength (light is made of electromagnetic waves!).
The offset speed would then just be something like MHz/s.
Polarization is actually quite tricky. An electromagnetic (EM) wave can be circularly polarized, linearly polarized, or elliptically polarized (somewhere in between circular and elliptical). In linear polarization the field oscillates back and forth like I described above, but in circular polarization it just rotates, and its frequency is how many full rotations it makes per second. Quantum mechanically, EM waves are made of a collection of particles, or quanta, called photons. Each photon may be left-circularly polarized (its field rotates counter-clockwise) or right-circularly polarized (clockwise), or a combination (superposition) of the two. If the photon exists with equal probabilities in the left- and right- state, then it's linearly polarized! If it's only in one of those states, then it's circularly polarized. If it's an uneven mix, then it's elliptically polarized.
If you have a bunch of photons traveling together with the ultimate destination being your telescope, then the electric field you measure will reflect their polarization. If they are all linearly polarized, then the field you measure will oscillate like I had described before. If they are circularly polarized, then the field will, instead of shrinking and growing, rotate. If they are elliptically polarized, the field will both shrink/grow and rotate, drawing out an ellipse. The complication is that, as is usually the case in radio astronomy, the photons may not all have the same polarization! In this case, the field you measure may have some particular frequency still, but the field will be pointing in all sorts of directions, neither drawing out a line, circle, or ellipse.
A single antenna can only measure the proportion of the electric field which is parallel to it, along the direction it is oriented. Now, if your antenna is oriented vertically, it can measure an EM wave that is polarized upwards or downwards (the distinction between the two is just a phase shift, half a period). If the EM wave is polarized horizontally, it won't really be able to measure anything at all. If it's at an angle, though, the antenna will still measure the EM wave, just less so. If we now add a second antenna which is oriented horizontally, making a + shape, we can look at the relative strength of the field as measured in each antenna to figure out which direction the wave is polarized. This is what is done in radio astronomy! Each telescope dish will have two antennae, roughly perpendicular to each other, to be able to measure any polarization.
Even circular and elliptical polarization is covered by this -- if both antennae reach their respective peak measured fields at the same time, the field is linearly polarized. If they get the same peak strength but one is at its peak while the other is at its minimum (zero field), then it's circular. And again, somewhere in between is the elliptical polarization.
Now here's the kicker. Not all the received photons may have the same probability distribution in the left- and right- polarization states, or even phase (if we care about coherence). If this is the case, then the photons may only be partially polarized: there is a bias towards a particular polarization, but not all of them have it. Or it may be entirely unpolarized -- their distribution is effectively random.
Now we get to the game. There are two controls here: the Polarization Filter offset (presumably the direction of linear polarization) and the Polarity setting (for left- and right- circular polarization). These are somewhat at odds of each other. If we had only the linear polarization setting, then that fully characterizes the linear polarization of a wave! If we have the left- and right- polarization, then we can look at either left-circular polarization only or right-circular polarization only. But if, say, we filter out all the left-circularly polarized signal by selecting the right-circular polarization setting, then the resulting signal is right-circularly polarized, not linear!
Now, without changing game mechanics, this setting should probably just be left as is. Technically, you'd only need 0-180 degrees of polarization to characterize linear polarization (if it's polarized in one direction, and you wait half a period, it's effectively polarized in the other!). Or if you just care about tuning the signal strength in each antenna, then 0-90 degrees is also OK. But if you care about the relative phase in each antenna, then 0-360 is needed. The left- and right- circular polarization may be better off being a last (or first?) resort when the signal is found to not be linearly polarized.
Or maybe a third setting under polarization, the ellipticity from 0 to 1, should be added to make it fully consistent. Then 0 ellipticity would correspond with having only linear polarization, 1 would be circular only, and somewhere in between is, again, somewhere in between: elliptical polarization. Then you'd just have to get the linear polarization (0-180 degrees), circular polarization (left- or right-), and ellipticity (0-1, unitless) correct to maximize the signal strength. That may be hard to do as the player without extra input, though.
If I were to suggest game-breaking stuff that probably veers away from its intention, it would be taking the time to sit and listen for signals. I'm thinking like in the movie Contact. Maybe you'd have one device that plots a live frequency spectrum or spectrogram to tell you what frequency to tune to. Then a device with which you select a linear polarization, frequency, and AM or FM (amplitude or frequency modulation, to determine how to create audio from it, maybe there are more sophisticated ways), until you actually hear what is going on.
There are other oddities too... it doesn't make sense to ping space looking for a signal. You'd be waiting hundreds or more years to receive an infinitesimally small pong! Maybe your supervisors would just tell you "listen to this object in the sky for this amount of time." And sometimes the object is just to be measured for some time and sent, or other objects would be SETI-like and you'd just listen until something interesting happens, then start recording and figure out the settings to get the audio.
Anyway, I hope you enjoyed my midnight rant!