The gate is opened from the Hell to the earth in London in Diablo fashioned way
In HGL you can create different types of characters depends on your personality of the play. You can be a blademaster, rifleman, engineer, summoner, and guardian. Each of these factions has special abilities. These abilities lets the person to do special actions which is unique. Each faction has also a skill tree which can spend his skill points to unlock or upgrade a skill to enhance the fighting against the enemy.
The target of the game is to kill the demons in the streets and in the sewers to accomplish primary and secondary objectives. Your primary objectives is the story line. But the secondary objectives can help you to gain special items or experiences.
Throughout the game you can collect items and use them. These items include armors, weapons, health injectors, power injectors and weapon modifications. Every items in the game can be upgraded using special terminals in the underground stations. These combinations of various items and upgrading of the items lets the user decide various ways to wear different types of armors and weapons.
Although the game has many alternatives to be played, but it is designed the same way that Diablo 2 was designed. After 10 years players are expecting something more innovative. In addition, in some part, the game becomes terribly boring and you pass several halls which looks like the same, you kill the same monsters and suddenly you feel bored but still hope it gets better. The problem is that the developers didn't spend much time designing each part, they used an automatic generating environment. This automatic generating environment, generate each hall as you go through it. What do you expect from a game that its maps is generated not designed? In developers opinion they took less time to develop a game but in the players opinion, the same environment for multiple locations makes the game looks boring.
If you look for something to remind you of the old Diablo 2 thing in a new DirectX 10 environment with good graphics I suggest to buy it but if you look for something new, you should check your alternatives.