Overdose lacks in what made the original Painkiller so great.
I played the first Painkiller game and its expansion, and what I've noticed is a degradation on the series. The original game was simply excellent, with an amazing background story and main character, imaginative maps, balanced selection of weapons, well-designed enemies and, most important, solid gameplay. The first expansion, although being a good addition, it's only a shadow of Painkiller. The same character became horribly ugly, the storyline wasn't interesting, and some levels were simply too annoying.
In Overdose, those problems become even more evident, plus some more issues were added as well. First of all, you play as a half-angel, half-demon creature named Belial. Here, this is basically the "Evil vs. Really Evil" thing, and I believe this is the reason why most of the levels look so... well, hellish. That red fog all over the place in some levels just shows the uninspired level design of this game.
There're new weapons as well, but most of them work exactly the same as the ones in the first Painkiller. The Razor Cube, BoneGun, Rocket Laucher and so, are just equivalent versions of the original arsenal, but with a different skin and sound effects. If I'm acquiring an add-on, I'm looking for something actually new, not recycled stuff. And here I'm almost not considering the really new weapons, because most of them are so useless and disappointing that it isn't even worth speaking about. No, let me give an example: there is this cursed broken dagger, named Shadow Blade, which fires a ludicrously slow and tiny projectile that doesn't seem to hit the target (especially if the enemy is sidestepping), although it's indeed effective when it hits. The Crossbow is also a bit odd, especially if you trigger the secondary fire, which launches a bunch of exploding skulls that will probably hurt more the player than the opponents.
Mindware also didn't bother with the multiplayer mode, since it's still very basic and competitive-only. Why they insist on the same mistake? A cooperative mode would be great to extend the life of the game and add variety to the gameplay. However players will probably have to rely on only the single player experience... again.
The most annoying aspect of Overdose is the loading time. It takes more than ever to just quickload your progress (actually more than a full minute), which seems endless when you're at some of the difficult parts of the game. There is a level somewhere at the end of the game, which I'll not spoiler what kind of map is, which made me almost give up. Not only because it was so hard, but especially due to the fact I had to wait a long minute to just retry and die again. I spent more than 30 minutes just loading the progress until I got tired and restarted the map. Maybe it was because I had chosen the "Nightmare" level of difficulty, which is a step above the default setting. I've read that it's almost impossible to finish the game at the hardest level, called "Trauma", although it was perfectly possible (and fun) playing the first Painkiller on this setting.
On the bright side, there are still a few maps which are definitely worth playing. These rare exceptions are probably better than the best maps of the first expansion and as good as the top levels of the original Painkiller. This gives a "thumbs up" to Overdose, and I found incredibly fun killing the hellish pets at the Animal Farm level, for example. I would like to say more, but I'll not spoiler anymore one of the few strong points of this game.
Another great thing in Overdose is the graphics, which look a bit better than the first Painkiller and its expansion. Too bad that most of the levels aren't so creative to enjoy this good looking engine. But you'll still like the exaggerated amount of blood and special effects, such as explosions, lightning, shadows etc.
The soundtrack unfortunately doesn't match my taste, since I prefer the heavy metal style from the first game. But this is a matter of opinion which isn't worth talking about. The sound effects, on the other hand, are still great and you'll enjoy hearing the noise of your skeletal shotgun firing against the bizarre monsters of Overdose.
Lastly, I'm pleased that Mindware kept the old-school feel that's all about shooting legions of enemies that attacks you from every possible side. In fact, they even spawn at places which you would never be able to predict, which is sometimes very irritating. But in general, the astonishing gameplay is nearly intact and this is a solid aspect in Overdose. If you think I'm being too harsh, it's because I want Painkiller the way it was back in 2004, but with real innovations. Gamers shouldn't accept every cool game as a masterpiece, because it would only make the developers to continuously release flawed and uninspired games. I think the right thing to do is to point all the possible negative aspects of the game, so future versions are made with a better presentation, which is something I really wish particularly for the Painkiller series.