No better way to start such an awesome series...
So, this game is just run and shoot at practically everything that is moving. Same as Doom, yeah. Then how come this game is so amazing? How can such an unoriginal game system become this acclaimed?
It's easy: this is probably THE non-thinking game. You'll pass 95% of the game running and shooting, 4% of the game staying still and shooting, and 1% of the game going to get next dozens of monsters. It could sound lame but it isn't. Now one by one I explain the reasons of this.
First of all, while gameplay is absolutely non-sense, and simple, it's well done. A dozen of characterized weapons, hundreds of different and easy-to-remember monsters, well done level designs, and linear but not boring fights are the heart of the game, and even if you'll need to resolve some "problem", they won't keep you busy more then 30 seconds. The places are a bit too similar though: it's all in Egypt!
The graphics, well, are amazing. They were, and they still are. When they came out amazed for it's awesomeness. Today it still amazes cause of the cleaniness of it. It's wonderful, with high quality textures, shadows, light effects, and a well-coloured and stylish world.
The sounds are cool too. Easy-to-recognize sounds of the monsters and of the weapons, with good ingame musics, and lots of funny jokes of Serious Sam. Right, because the game is full of these crazy jokes of Sam! I won't spoil the (really simple) game story, but one thing is sure: it's hilarious!
As for value, well, it's hard to tell. I played this game till the end different times, so the replay value is high. The multiplayer is pretty strong, with a decent deathmatch mode, and an amazing cooperative mode, that practically doubles the already sky-high fun of the game. And at the budget price it is sold at, it's absolutely a must have, no matter if you like FPSs or not.