Special Upgrades are upgrades which gives miscellaneous changes to the game Monster Box. These upgrades can either require Money or Jewels (and are categorized as such in the app version's interface). Currently ten special upgrades are available.
- Mouse Accelerator: This upgrade increases the rate of charging the monster box by clicking. The rate start at ×4 (15s per spawn), and each LV increases the multiplier by 4. Costs $(10n+1) for the nth upgrade. The maximum LV of the upgrade is 9, which corresponds to a maximum rate of ×40 (1.5s per spawn).
- Maximum Monster: This upgrade rise the limit of monsters on screen before causing a game over. Costs $(10n+3) for the nth upgrade. The limit starts at 1000 and the maximum LV of the upgrade is 9. Upgrading to LV 1-4 adds 250 to the limit, LV 5-8 adds 500 and LV 9 adds 1000. Thus the maximum limit can be raised to 5000 (1000+250×4+500×4+1000).
- Money Bonus: This upgrade increases the money drop of all enemies by the specified amount. Costs $(10n+1) for the nth upgrade. Bonus for each level are 1, 3, 5, 10, 15, 25, 40, 60 and 100. When money multiplier is activated, the bonus by this upgrade is added before the multiplier.
- Money Boost: This upgrade multiplies the money drop of all enemies by the specified amount. Costs $(10n+2) for the nth upgrade. The multiplier starts at 1.0 and each level adds 0.1 to the multiplier. The maximum multiplier is 2.0 which is reached at the 10th upgrade. This boost is calculated after the Money Bonus is added.
- Max Time Bonus: This upgrade increases the maximum time bonus allowed. The rate start at 2×, and each LV increases the multiplier by 0.2. Costs $(10n+1) for the nth upgrade. The maximum LV of the upgrade is 10, which corresponds to a maximum rate of 4×.
- Time Bonus Interval: This upgrade reduces the time required for each time bonus increase. The time taken starts at 60s, and each LV reduces the time by 5s. Costs $(10n+1) for the nth upgrade. The maximum LV of the upgrade is 10, which corresponds to a minimum time of 10s.
- Max Player LV: This upgrade increases the maximum level allowed for all stickmen by 10 per upgrade. The nth upgrade requires 5×n Jewels. With a maximum of 200 Jewels available, the current maximum player LV is 180.
- Monster Selection: This upgrade reduces the pop count for all stickmen by 10% per upgrade and increases gold drop to (10/(10-LV)) times the base value. The nth upgrade requires 5×(n+1) Jewels, making the maximum values -70% and 3.33× with a maximum of 200 Jewels available.
- Multiple Boss: This upgrade allows multiple bosses of the same type to coexist on the game screen, up to 10 bosses where the upgrade is maxed. Each upgrade requires 5 Jewels.
- Box Acceleration: This upgrade increases the idle charge rate of the Monster Box and also gold drop. Each LV increases the charge rate multiplier by 1 and gold drop multiplier by 0.1. Each upgrade requires 5 Jewels. The maximum LV for this upgrade is 10 which gives 11× charge rate and 2× gold drop. Note that charge rate boosts are additive with other charge rate boosts, e.g. Clicking the monster box with LV 1 Mouse Accelerator and LV 1 Box Acceleration gives a 9x charge rate (+100% from Box Acceleration and +700% from clicking with Mouse Accelerator, for a total of +800% charge rate, i.e. 9x charge rate).