What do you think about playing a medieval/fantasy version of DOOM?
Heretic: Shadow of the Serpent Riders (aka Heretic v1.3) is just like having The Ultimate DOOM. Back in 1994, Raven Software released the first Heretic, which features three chapters, each one with 9 levels (one been secret). Just like the original DOOM, you can finish the whole game pretty fast, even on higher difficult levels. This new Heretic version adds two episodes (or 16 new regular levels and two secrets), which are much harder than the first three. As you can see, it's pretty much like The Ultimate DOOM, which has a more hardcore-focused new chapter, especially made for experienced players.
Aside the new maps, there is nothing new in Heretic v1.3. You play as a mage that can handle a variety of magical staves, and your objective in every map is to find a magical switch or a teleport that will bring you to the next level. While you try to find the end of each map, you'll fight against several different monsters, from the weak gargoyle to the powerful minotaur. Each enemy has a particular behavior. For instance, the stone golem is pretty dangerous at close range, but isn't a threat if you stay far away from him. But take care, you may find some golems that can fire at distance, as well invisible ones that may surprise you in a dark room. The gargoyle has also a ranged version, while the great majority has only melee attacks. The necromancer (actually a big, iron flying head) can attack with three different spells: a whirlwind, a flame wave and an iron ball, very difficult to dodge. Another very common enemy is the undead warrior, which fires magical axes and can also appear partially invisible sometimes (which become particularly dangerous).
Your weapons are quite different from each other. You start the game with a very weak crystal wand, and then you upgrade to the crossbow. This weapon will be used in the entire game, and will be your standard combat tool in most situations. Then you find the dragon claw, which works especially well against moving targets. The last three weapons are a bit rare to find, and I'll not spoiler them here. Let me just say that you'll receive an area effect staff, which must be used without hesitation against powerful opponents. There are melee weapons as well, that you'll probably use only at the init of each episode (this is, when you don't have enough ammunition): a lightning gauntlet and a quarterstaff. These weapons aren't completely useless; however you'll find yourself using more the ranged stuff.
If there is a thing that Raven Software tried to innovate, it's definitely the use of special items. These artifacts are kept in your inventory, and they must be used depending on the situation. The torch is a must-have item when you're exploring a dark room, otherwise you will probably be attacked by an invisible golem and you'll never find where he is. The torch is also a good option if you're looking for a particular switch, which is hard to spot sometimes. Another trivial artifact is the Quartz Flask, used to restore 25 points of health (when you cannot find the regular healing potions). The Tome of Power is also very important, because it boosts the strength of your staves for a short period of time. But, in the way I see, the most useful one is the Ring of Invulnerability, which must be used when you're surrounded by lots of enemies, or when you're facing a giant minotaur. All items disappear when used, but you'll find plenty of them in the levels, especially if you have enough patience to search for secret passages. I also noticed, at least on the highest difficulty level, that the game only allows you to carry one type of artifact when you finish a level. All the extra ones are lost. This may sucks but, in truth, it's a good reason to try and spend your special items, instead of just keeping them until you reach the final map.
As I said before, the first three episodes are a bit easy, but I think that everyone will find the boss battles interesting. To be honest, D'Sparil, the final boss of the third chapter, is one of the toughest guys I ever met in a PC game. I was playing on the last difficulty setting, and make no mistake, it's punishing. But it's also a very rewarding experience, because you'll get a lot of enemies to kill per map (usually more than a hundred), and you'll find yourself trying several different tactics to beat the hordes of bad***es. For example, I always like to wake up all the enemies in the map and then find a safe place, so I can kill one enemy after another without any hurry. Another cool strategy is to find cover behind certain obstacles (actually those 2D sprites), where enemies cannot hit you, but it's possible to use the crystal wand or the dragon claw to fire through the obstacle and easily beat them.
The two new episodes in Heretic v1.3 were designed for hardcore players. You start the map usually surrounded by a lot of monsters, and you don't have enough ammo and even the best weapons to deal with them. As I said above, a bit of strategy comes handy. The run-and-gun tactic may work in the easiest difficulty settings, but they aren't effective in the harder ones. Anyway, the levels aren't as confusing as the ones we sometimes get while playing DOOM. I had some headaches with the fifth chapter, where I had to find keys and switches in literally secret places, often a bit hard to spot. But the levels in Heretic are usually very straightforward.
If the single player isn't enough, you can play the campaign with another three players, or try some deathmatch games against them. As you can see, Heretic v1.3 offers 45 levels for both the competitive and cooperative modes, which is more than you need for your multiplayer enjoyment. It may be a bit hard to make Heretic run in modern PCs, so you can always use enhanced Win32 ports (such as ZDoom or Doomsday), or you may also experience the original feel by trying a MS-DOS emulator (DOSBox or VDMSound). If you liked DOOM, you'll find Heretic: Shadow of the Serpent Riders a good option to once again try something suitably old-school.