Not as great it's prequel. It was seriously too silly.
One of the bigger problems that I have with this sequel, is that it is too colourful. Now you may not think this is much of a problem but it is so colourful to the extent that your weapons feel like toys and the silliness of the game is taken a bit far. And the weapons are so ‘futurised’ and have new appearances (e.g. the revolving shotgun or the gauges on the cannon) that it feels you’ve gone from Serious Sam: The Second Encounter into Sci-fi Sam. Almost as if the developers thought that more is better but in this case I felt they crossed the line of ‘too much’.
The voice acting on Sam’s part wasn’t that great. Not necessarily the voice acting itself but the way it’s played back sounds like Sam is speaking into an old microphone and the sound is coming over old, scratchy speakers. This seemed odd since he is standing right in front of you so I don’t know why it should sound like this. Other voices are done well, such as Netricsa (your onboard computer).
The other problem is that everything is a lot sillier. Once again I feel that they crossed the line from ‘more is better’ to ‘too much is worse’. For example in The Second Encounter there was a fair amount of silliness but that was usually contained in the secrets but now it has leaked into the game right up into your face.
The action, albeit repetitive, was fun. The same expected gun-down-the-attempt-at-the-record-for-most-onscreen-enemies. Although once I finished the game I put it down hoping that the next Serious Sam will be based more on the Second Encounter and not Serious Sam II