excellent
when i saw this on the front page, i was a little cynical, especially after Mike's Doom port. but this was a very fresh and fun take on the classic game. the use of actual sprites was excellent and it was fun. i also very much liked the background and the parallax was nicely done. i found it a little odd that the enemies could see you no matter what when you entered a room they were in, even if they weren't facing you, but health packs were generously littered throughout the levels and it wasn't a big deal. the controls were tight and responsive and i didn't find any glitches regarding them.
i think the one thing that REALLY bugged me was the omission of the health portrait. you had the sprites (like in the icon for this and for the difficulty selection), so i'm a little confused on why you left that out.
other than the small annoyances above, this is a fine tribute to id and to Doom. awesome work (: