Totem Collection Event (BTD6)

Totem Collection Event was an event in Bloons TD 6 released on 27th/28th February 2020, one day after Version 16.0. The player received totems for every finished map, together with ordinary rewards such as Monkey Money or medals. A number of totems was based on a game and track difficulty. After collecting a certain amount of totems, the player was rewarded with a crate. After opening the crate, the player received two (or three on later stages) Insta-Monkeys. As the player collected more totems, the crates increased in quality, requiring more totems to open but yielding higher quality Insta-Monkeys in turn.

In 2020, the Totem Collection Events lasted as follows:
 * 7 days, from February 27th/28th to March 4th/5th.
 * 7 days, from June 2nd/3rd to June 9th/10th.
 * 7 days, from August 15th/16th to August 22nd/23rd

In 2021: the Totem Collection Events lasts as follows:
 * 10 days, from February 11th/12th to 21st/22nd
 * 10 days, from May 27th/28th (28th May, 10:00am NZST) to June 6th/7th (June 7th, 8:00pm NZST)
 * 18 days, from August 25th/26th (26th August, 8:00pm NZST) to September 12th/13th (13th September, 8:00pm NZST)

Totem rewards (2020-Present)
For the first event, Totem rewards for finishing a map were following, for default values:

The second event gave more Totems than the first event overall. Subsequent totem events used this formula.

However, the rewards can now be boosted if they become the Featured Totem Map for their map difficulty category. One random map from each of the map difficulties (Beginner, Intermediate, Advanced, Expert) will be chosen as the Featured Totem Map. These maps will randomize again every 8 hours. Note that all of the maps randomize again once a map has been beaten, not including if a totem status was done already.

The following values are increased to as shown below, for the first event:

And increased yet again for the second event, and same with starting from 2021:

Crate rewards (2021)
Each new tier of crate was unlocked depending on the number of totems collected:
 * Wooden Crate (Tier-1) - Default
 * Bronze Crate (Tier-2) - 100
 * Silver Crate (Tier-3) - 250
 * Golden Crate (Tier-4) - 450
 * Diamond Crate (Tier-5) - 1000

Each type of crate required a specific amount of totems before being allowed to collect the crate's special Instamonkey rewards:
 * Wooden Crate (Tier-1) - 20
 * Bronze Crate (Tier-2) - 30
 * Silver Crate (Tier-3) - 40
 * Golden Crate (Tier-4) - 50
 * Diamond Crate (Tier-5) - 70

Because of the new modification to all Collection Events, 1 of 4 tower types of Instas are able to become selected as the favored tower type, each with up to 5 uses each. When a tower favor is selected, all Instas from that chest will only spawn the same tower type; otherwise it will spawn random Insta tower types as normal. All tower favors reset every 8 hours (4:00 UTC, 12:00 UTC, 20:00 UTC), and will respawn a different set of 4 towers with 5 uses each.

Each type of crate rewarded the following Instamonkeys:
 * Wooden Crate (Tier-1) - 80% tier 1, 20% tier 2, always 2 insta monkeys
 * Bronze Crate (Tier-2) - 20% tier 1, 70% tier 2, 10% tier 3, always 2 insta monkeys
 * Silver Crate (Tier-3) - 40% tier 2, 55% tier 3, 5% tier 4, always 2 insta monkeys
 * Golden Crate (Tier-4) - 60% tier 3, 40% tier 4, 10% chance to have an extra insta
 * Diamond Crate (Tier-5) - 35% tier 3, 60% tier 4, 5% tier 5, 40% chance to have an extra insta

Crate rewards (2020)
Each new tier of crate was unlocked depending on the number of totems collected:
 * Wooden Crate (Tier-1) - Default
 * Bronze Crate (Tier-2) - 90 (100 for event 1)
 * Silver Crate (Tier-3) - 230 (250 for event 1)
 * Golden Crate (Tier-4) - 350 (450 for event 1)
 * Diamond Crate (Tier-5) - 750 (1000 for event 1)

Each type of crate required a specific amount of totems before being allowed to collect the crate's special Instamonkey rewards:
 * Wooden Crate (Tier-1) - 20
 * Bronze Crate (Tier-2) - 30
 * Silver Crate (Tier-3) - 40
 * Golden Crate (Tier-4) - 50
 * Diamond Crate (Tier-5) - 70

Because of the new modification to all Collection Events, 1 of 4 tower types of Instas are able to become selected as the favored tower type, each with up to 5 uses each. When a tower favor is selected, all Instas from that chest will only spawn the same tower type; otherwise it will spawn random Insta tower types as normal. All tower favors reset every 8 hours (4:00 UTC, 12:00 UTC, 20:00 UTC), and will respawn a different set of 4 towers with 5 uses each.

Each type of crate rewarded the following Instamonkeys:
 * Wooden Crate (Tier-1) - 2 Instamonkeys, Tier-1 (high chance) and Tier-2 (low chance)
 * Bronze Crate (Tier-2) - 2 Instamonkeys, Tier-1 (low chance), Tier-2 (high chance) and Tier-3 (low chance)
 * Silver Crate (Tier-3) - 2 Instamonkeys, Tier-2 (high chance) and Tier-3 (low chance)
 * Golden Crate (Tier-4) - 2 or 3 Instamonkeys, Tier-3 (high chance) and Tier-4 (low chance)
 * Diamond Crate (Tier-5) - 2 or 3 Instamonkeys, Tier-3 (medium chance), Tier-4 (high chance) and Tier-5 (low chance)

Trivia

 * New feature of random map bonuses were added to all future Collection Events to provide a more viable option than simply grinding Dark Castle Easy repetitively. Players could use autoclickers in order to generate heaps of Collection Event currency every 5-6 minutes of playing Dark Castle Easy. Additionally, this change makes it more fun to play Expert Easy manually on multiple Expert Maps.
 * As of the 2020 Totem Collection Event, save files prior to the event will no longer count towards collecting totems.
 * Apparently, if the player had played on an old save and won on a map with a totem bonus, the totem bonus will still move on to the next map.