Couple things to keep in mind.
1) No multiplayer at all on the PC version. Considering how much I loved these games for multiplayer alone, it's kind lame.
2) So-so port. It's functional, but there's no graphic options or anything like that. Pretty par for the course for PC versions, but some might get a bit upset.
Still, I did love these games.
MonstaMunch: This looks fantastic, but I'm a bit confused by the mechanics. One of the reasons I always preferred the original over the sequels was that it didn't have the manuals and reverts, which left the up/down buttons free for other stuff. I felt the addition of it just made things a little too messy. Now I'm reading that this version is some hybrid of the first two, though also with elements of 3 (such as reverts). This all leaves me a bit confused as to how it's going to play, as the first three versions all had a distinctly different feel in terms of controls.
Still, I'm willing to find out for $8.99....
Basically the only extra mechanic in this package is manuals. There's a DLC pack consisting of levels from THPS3 coming out, and reverts will be enabled for those levels since they were designed around it. Reverts won't be brought over to the older levels since they weren't really designed to accommodate for it.