@kycnotme I think the rating should be lower (currently it has 10), but I'm not sure about the exact number.
I did investigate it further and had a look at their code:
https://github.com/tecnovert/basicswap
The readme says it's in beta, so it is possible that some features have not been implemented yet (the website, however, presents BasicSwap as a finished product). I was able to locate code that does BTC-XMR atomic swaps, and @kayaba suggested that their implementation could be real. I didn't find atomic swap implementations for other currencies listed on the website.
The orders are sent to a local Particl node. It's a fork of Bitcoin Core with various additions, so the P2P network is probably real (Bitcoin Core provides that), but it is not clear how decentralized it is.
The Particl blockchain is a PoS chain powered by the PART token, which lost 99.48% of its value since ATH. I think it is reasonable to assume that the people behind this project are the only ones who hold significant amounts of coins, because everyone else had quit long time ago. And since it's PoS, this means they have total control over the chain, and in my view that makes it equivalent to a single server.
I can't find any information about past security incidents, apart from this strange github post talking about an inflation bug: https://github.com/particl/ccs-proposals/pull/5
Particl-Core and most of BasicSwap were developed by a single person.
So my conclusion is that foundations for "Privacy-First Cross-Chain DEX" might be present, but the product is presented in a misleading way, not properly documented, and not independently audited. Furthermore, the market valuation of PART token indicates an extremely low trust in it, which might have caused by past incidents.