It's a fun and, to some extent, a mindless FPS game. Not bad at all, but not great either.
Good stuff:
- fun shooter (better than average)
- pretty good presentation considering a rather shallow story
- decent graphics and sound quality
- most people can play it in terms of their equipment and gaming skill level
- weapons "feel" good when fired (and they do some serious "graphically explicit " damage to the oponent; recoil feels right too)
- after playing for months games where you can't jump or jump over (including some "realism" games like GRAW), it's simply refreshing to be able to do that again.
Not so good:
- dialogs -- if they were not present nobody would notice
- story -- maybe a fun shooter doesn't need one
- short game -- it's short, but it's also $20 (and not $50)
- weapons look cartoonish (pistol for example looks like an industrial strength staple gun)
- "Steam" -- I've never understood the concept. Why would I need an online account if I have their DVD? I'd appreciate more a standard website with downloads, patches, etc. rather than something that always connects to the Internet. This becomes a very bizarre requirement in games like this one that don't even have a multiplayer component.
- no multiplayer
- the concept of "episodes"? -- make a full-featured game and call it as you wish. Why not simply SiN 1, SiN 2, etc . ... there's no story or some deeper meaning here to be serialized. It looks more to me as ... "we need some cash flow and we don't have a finished full-featured product".
But beside my subjective negative comments above, the game is enjoyable and it could be fun for most people who like FPS games.