I think the Siren Song is a bigger threat on paper than it is in game really.
eye contact prompts a Sanity save, if failed then under the effects. Even then its just a slow burn of increased stress gain until a failed panic check causes you to lose control of the PC until wounded (which im changing to [-] Sanity save when damage taken to clear the effects)
The Siren IS a force to be reckoned with as it is the only external threat... that said there is a laser cutter with 1D100 DMG stashed in the comms tower that can one shot the thing potentially.
With it being such a fast and deadly mission, I wanted direct engagement with the Siren to be very deadly without a solid plan. eg. using the fire extinguisher to obscure its vision, or causing an explosive decompression event in a "take us both out" move. hell even the geography of the moon could create a potential Terminator 2 cryo death scenario with the freezing methane geysers.
I think there are a lot of tools to solve things in creative ways, but reflecting on your comments, I think they could be flushed out more, especially for the "turtle" option of not ever leaving the lander.
Viewing post in There's Something Outside the Lander jam comments
Okay, I think I made a bad assumption. I read it as: Fail Save -> 1D5 Stress -> Immediate Panic Check -> Mind-Controlled if that fails too.
If fully falling under her sway is only possible if something else causes a panic check... well, she could still kill someone else on round one to force it. However, that does now require four separate rolls to all go badly... fail save, then she rolls to hit, rolls high on damage and one-shots your buddy, you fail the panic check...
It's not likely to happen, even under my original assumptions. And you're right that it's "fair" in that they could equally one-shot her. But either of those things could happen quite early on in a perfect storm, and I'm instinctively averse to front-loading decisive rolls in that way. I want to be sure there are going to be at least a couple ebbs and flows of tension before we get to the point that the whole thing could be over on the next roll.