Book of Dead is a thrilling online slot game that is inspired by the age-old fascination with ancient Egypt and promises to keep you on the edge of your seat. It was first launched in January 2014 by renowned gaming company Playn Go. Below are the critical features and mechanics of the game.

Gameplay:
- The game follows the exciting journeys of the Indiana Jones-like character, Rich Wilde, who is on a quest to uncover ancient artefacts.
- It features 5 reels, 10 paylines and high variance gameplay, where payouts can be quite substantial once they occur, promising a thrilling gaming experience.
- This game has 11 symbols in total, including one that acts as both a scatter and a wild symbol.
- It is fully optimized for mobile and supports gameplay on a variety of devices including desktop, laptop, tablet and mobile.
- The maximum winning is 250,000 coins.

Graphics:
- The graphics are quite engaging with symbols and background images inspired by ancient Egypt, adding to the appeal of the game.

Bonus features:
1. Gamble Feature: You always have the option to gamble your winnings by guessing the correct color or suit of the next card to be drawn, potentially doubling, or even quadrupling, your winnings. The risk is, of course, that you may lose it all.

2. Free Spins: The free spins feature is triggered when at least 3 Book of Dead scatter symbols are landed anywhere on the reels. This immediately provides you with 10 free spins, and the number can be increased by landing additional scatters during the free spin rounds. One symbol is chosen randomly before the free spins start, and it expands to cover a full reel if a winning combination is possible.

Technical details:
- RTP or Return to Player: 96.21 %
- Volatility: High
- Layout: 5x3
- Paylines: 10
- Bonus features: Expanding Symbols, Free Spins, Risk (Double) Game, Wilds
- Max wins (coins): 250,000

The game's popularity speaks to its quality and the level of enjoyment that players can expect. Whether you're a casual gamer or a high roller looking for the next big winning, ”Book of Dead” offers something enjoyable for everyone.