Yeah I listened to game dev club on SS2, including the interviews about it.
SS2 imported the engine (obviously) from Thief, including the crappy visuals and awesome sounds. It imported the giant spiders. But because they upped the engine to 16 bits and probably due to time limits, they couldn’t maintain the same size of levels the Thief engine supported (which is part of what made it great), and stealth is pretty much half-assed in SS2 – it’s in the engine, but it’s very hit or miss. From SS1, SS2 got the diaries (which were novel at the time), the survival-horror atmosphere, backstory, the concept of enhancements, and SHODAN.
The RPG system was new, but I also think it’s incredibly lacking. Mostly, I think the project suffered from not enough development time – it feels rushed everywhere, and it suffers from the worst malady of RPGs – you need to make choices about your character before you know what you’ll need, and making the wrong choice can doom you to failure.