Tombstone No Mercy, developed by NoLimit City, is an enhanced version of the previous Tombstone slot game. The game has a Wild West themed with many exciting features and mechanics that cater to various players. Here is a list of some of its game mechanics:

1. **xBet Options**: Tombstone No Mercy introduces the inclusion of several xBet options, which can significantly enhance potential earnings.

2. **Bonus Buy Options**: The slot game also offers bonus buy options, which might lead to major payouts.

3. **xNudge Wild Action**: This feature is maintained from the previous game, allowing you to experience plenty of xNudge Wild action at all game stages.

4. **Slot Theme and Storyline**: The game takes you back to the Wild West, promising a gritty experience filled with high-stakes duels.

5. **RTP**: Standing at 96.05%, the return-to-player percentage is just above the industry average. But keep in mind that this can be adjusted depending on the market.

6. **Volatility**: Tombstone No Mercy is a high volatility game, scoring a perfect 10 on NoLimit City's volatility scale.

7. **Max Win**: The maximum win in this slot game is 16,480 times your stake.

8. **Gameplay**: The game comprises five reels, two rows on reels 1 and 5 and three rows on the middle three reels, amounting to 108 ways to win.

9. **Symbols and Paytable**: The slot game includes dynamite, gold bars, moneybags, and many more. Notably, the $$$ scatter can trigger Gunslinger Free Spins.

10. **Bonuses and Special Features**:
- *Scatter Outlaw xBet option*: This feature guarantees an Outlaw Wild or a scatter per spin.
- *Outlaw xNudge Wilds*: The 3 different Outlaw Wilds nudge into place to cover the full reel they appear on, thus increasing the wild multiplier.
- *Free Spins*: Provided by three types of Bonus Rounds - Justice Spins Feature, Gunslingers Spins Feature, and Bounty Spins Feature.

11. **Bonus Buy**: This feature, available in select jurisdictions, grants access to options including Gunslinger FS, Bounty Spins FS, Lucky Draw 1 & 2, and Justice FS at varying stake costs.

In a nutshell, this enhanced slot game version offers various opportunities to claim big wins, coupled with the captivating Wild West theme, appealing storyline, RTP, high volatility, and an array of thrilling features that keep the game exciting till the very end.