When I looked at the screen-shots for Serious Sam 2, I thought it looked interesting, but was worried that they may have tinkered with the style in the previous games a bit too much. I think it's important to keep the essence of the game intact whilst introducing new ideas to make a great sequel. With Serious Sam 2, I think they have missed the mark for the most part.
The game begins with Serious Sam being summoned before the Sirian Council where they explain that he must collect all five pieces of an ancient Sirian medallion, each located on five different planets. Once the medallion is complete, Mental will be vulnerable. The players will meet non-player characters throughout the game who can provide extra power-ups or even join in the battles. NETRICSA, the computer system that provides Sam with information, is now an AI that talks to Sam. The story is developed through the use of cut-scenes (which are pretty low quality), which occur at the beginning and end of each mission. These scenes are silly, but often make you smile. It's an interesting direction, since the dialogue is often childish and the new graphical style is more bold and colourful, but a FPS can't really be aimed at kids.
The world seems a more interesting place since Sam visits many distinct planets with many different alien races and enemies. Some enemies are just remakes from the original Serious Sam, such as the were-bull, the beheaded kamikaze, the Scorp-soldiers and the galloping skeleton Kleer; while others are completely new to the series such as the suicide clown, martial arts zombie, zombie stock-broker, spiders, and helicopter. The enemies that return have lost their distinctive look. The beheaded kamikazes with bombs in their hands now have bombs for heads and springs for necks. The large Mechs have dinosaur heads, and the were-bulls have wind-up mechanisms on their backs.
Serious Sam was all about having a crazy number of enemies that were pretty strong and put up a fight. In this sequel, they are slower and attack in less numbers. During the first 45 mins or so, the game is a bit of a 'walk in the park' rather than been the crazy shooter the series is known for. You mainly walk through the level shooting a batch of enemies here and there, and the levels are over pretty quickly. After this point, it does start to be more like the old games and progressively increases intensity until the final parts of the game, where it does seem to get close to the old Serious Sam games.
There are a few sections that seem too hard, but it's different to the previous games in which it seemed hard but you are determined to replay and eventually overcome the section. In this game, you end up replaying but feel frustrated that you have to. The reason is that I felt the deaths seemed cheap. For example, in the first world where shot-gunners keep spawning. The shot-gun seems far too useful at range and the enemies spawn too quick, sometimes right next to you. So your health just drains and there's not much you can do about it. You end up dying because the game is unfair, rather than due to skill. Apart from these sections, the game will feel too easy if you have made your way through the previous games.
There are vehicles to ride as well as stationary turrets to utilise. There's quite a few ideas used throughout the game: dinosaur, rolling spiked ball, hover-crafts. I always feel these sections are the worst parts of FPS games and it's the same in this game. It feels mindless and boring, rather than the frantic action packed game-play you expect from Serious Sam. Luckily, these sections are over very quickly.
Most weapons were recycled from the original Serious Sam games such as chainsaw, pistols, shotguns, mini-gun, rocket launcher, grenade launcher, sniper rifle, the cannon and Serious Bomb. There's a few new ones too: Klodovic (a kamikaze parrot), an energy pistol, a plasma gun (which is similar to the Laser Gun from the previous games). You can launch grenades at any time by pressing the right mouse button which is very useful. The weapons don't seem to have the same punch they had before and they seem a bit different in their performance. In the previous games, you needed to pay close attention to the sound. Kamikazes will scream, Kleer will gallop, Scorpions will hiss, Were-bulls will moo. You then need to ready your preferred weapon for the scenario. Although enemies do make sounds in Serious Sam 2, it isn't as vital to pay attention to them, which is due to the smaller amount of enemies and slower movement speed. Additionally, most of your weapons work perfectly fine in almost all the situations, therefore you can rely on a select few weapons rather than having to constantly switch them out.
Although there's more variety of locales and enemies, the tweaks they made to the enemies and weapons has changed the game for the worse; this game lacks the intensity of its predecessors. Although there's still plenty to shoot throughout the game, you never laugh at how insane the game is like previous games until the final stages. You feel like you want to stop playing because you are bored, rather than stopping because your fingers are tired. It's still good for a quick pick-up and play and it's certainly fun for a short time, but it doesn't match the greatness and rarely matches the insane intensity that the other games achieved.