The Thompson's Machine Gun is better known as the Tommy Gun and has a rapid fire rate, but uses up ammo quickly. Also, there's a number of dynamite bundles scattered around the place. Five types of armour , plus Life Seed and Essence will help you out. A number of other items available require you to initiate them when you find it. Example's are a Doctor's Bag which contains 100 points of health and allows you to top up your health as and when you need it.
Some areas are accessible only with special keys hidden in each level.
Others require you to solve a puzzle such as restoring power to an area, or providing a specific combination. Yes, Blood is a Doom clone, but in as much as Duke Nukem 3D was. Like those two games, sprites are used in this game instead of polygons which gave Quake a more polished look, but slowed the gameplay down a tad unless you have a fast Pentium machine. The sound, like all the above, is a combination of sound effects from your weapons, the enemies, some ambient sounds, plus the occasional words from yourself - sometimes you even burst into song. Playability is nothing short of excellent.