Hot Blox is a uniquely designed online slot game created by High 5 Games. This game separates from traditional setups by incorporating a 3x3 grid for its reel set, divided into nine mini slots. Each mini slot looks like a block or box containing two reels and two rows, providing four symbol spots per block.

Game Features and Mechanics:

- Unique Setup: The game has a 3x3 grid, each segmented into nine mini slots or blocks.

- Symbol Fusion Feature: A match of the same symbol on all four reel positions in a single block merges the symbols to create a larger, 2x2 symbol. Only this mega symbol is eligible for creating winning combinations on the main grid, which requires at least 3 matched mega symbols to result in a win.

- Multiplier Boosts: Each block in the grid contains a meter that starts to fill up with every non-winning spin. If a winning block isn't fully charged, the meter is reset.

- A meter requires 18 non-winning spins to fill up.
- A filled meter results in a multiplier boost, the scale of which is determined by the number of fully charged blocks involved in the winning combo.

- Range of Multipliers: The multiplier values can range from 2x for a single charged box to a 100x for nine charged boxes, with the boost increasing incrementally as more charged boxes are involved.

- Charged Boxes and Free Spins: Any box not included in a winning combination for 20 consecutive spins will get fully charged for the next four rounds. This situation can occur simultaneously to multiple boxes, or even randomly occur to boxes that have been left out for 15 turns. Changing the bet level resets all the charges.

- Bonus Round Trigger: The bonus round of ten free spins is triggered when at least three blocks are filled with the 2x2 diamond scatter. The round cannot be reactivated, but a random number of fully charged boxes will be presented at the beginning to increase the likelihood of winning a multiplier boost.

- High Volatility: The game's high volatility might require consistent gameplay to finally hit the bonus round.

In summary, Hot Blox offers a fresh take on online slot games with its unique grid and mini slots arrangement, symbol fusion technique, and the addition of charged multipliers making the game an experience full of possibilities. With every spin and non-win, your potential for bigger wins increases!