One of my favorite in BTD Battles (flash) early game, as Ring of Fire do ultra well in Defense Mode and Blade Maelstrom can be used to destroy "surprise" Regen Rainbow Rushes in Assault Mode. In Bloons Monkey City and its mobile version, I also like to use Blade Maelstrom Abilities to destroy dense Ceramic or Rainbow rushes and a bunch of them together upgraded to Tack Sprayer can damage boss bloons very hard. However, In BTD5 and Bloons TD Battles Mobile, this tower has the same uses.
Dart Monkeys are pretty useful in Bloons Monkey City and its mobile version overall. In capturing normal Tiles, they can go early game with Triple Darts, Juggernauts, and Super Monkey Fan Club can still go late game pretty well. In BTD5, they can be a cheap tower to help 2/x Monkey Subs to increase their range (also applies to Bloons Monkey City Mobile). In Bloons TD Battles Mobile, this is an extremely useful tower. If you didn't know, using Dart Monkeys as a main force to pop bloons with support of Farms are the most popular way among experts. Triple Darts can be used as a main force early game, Spike-O-Pult can be used to destroy yellow rushes in a cheap price, Juggernauts can be used to destroy leads, ceramic and bigger rushes with few of them together, and Super Monkey Fan Club can go late game well with support. However, this does not apply to its flash version and it is not recommended to use in the flash version.
This is one of my favorite tower. In BMC flash and Bloons Monkey City Mobile, I always use 4/2 ninjas for starting, and I always use 0/4 abilities (Sabotage Supply Lines) in Contested Territory to slow down the bloons. In BTD5, the ability is also a must to go to late rounds, like 120+, and always act as a good starting tower. In BTDB, this tower can also be extremely useful. This can be used to be a good starting tower in Defend Mode. This is also an especially useful tower in late game for either Defend Mode and Assault Mode because of the ability. However, it is not that popular in the mobile version but the distraction upgrade is still used for Ceramics and the ability too.
A fairly good tower. In BMC, it is definitely the worst tower in tiles as a lot of rushes appear and they are not suitable for them. However Cripple MOABs is excellent in CT and Supply Drops is useful in CT when Banana Farms are restricted. In BTD5, this is not that useful. In BTDB, it is a little bit useful. In the Indoor Pools track in Defend Mode, this tower is a must for Lead Bloons in round 14. This tower upgraded to Night Vision Goggles and Full Metal Jacket can also be used in BTDBAssault Mode for beginners to pop CamoLead cheaply. However this is not a guaranteed choice for experts or experienced players. In the mobile version, it is not that popular and useful because it is too expensive and money controlling is very important in battles.
Very good tower somehow if you want to go late game. In BTD5, this tower is the least useful in early rounds. However, this tower is the must to go to high rounds like 130+. Spamming full sacrificed TOTMGs all over screen can go to ridiculously high rounds. In BMC, capturing tiles, they are useless. However in CT, again same as BTD5, this is the most useful tower if it is a full sacrificed TOTMG. In BTDB this is a useless tower. Additionally, Robo Monkeys can do well in BTD5 in mid-rounds and the Technological Terror upgrade can be a life saver for BFB rushes.
Ranked 2nd in all towers! In fact, it is the best tower against Boss Bloons in BMC, excellent tower in Contested Territory and fairly good tower in Tiles and Monkey vs. Monkey attacks. I always use Spiked Mines or Spike Storms when I have enough money. One of my ideas is to use Spike Storms in CT for late levels and Spiked Mines in mvm attacks/tiles. I also use 2/3 for the Dreadbloon and 1/3 for the Bloonarius. In BTD5, one Spiked Mines put in a correct location can surprisingly be used as a single to pop bloons not leaking up to Round 62 if the track is long enough and only has one exit. This tower is seldom used in late game. However, in BTDB, this is the best tower to go to late game in both modes and can go to a surprising high level: like 70 with some support. Of course, using Spike Storms. Differently, this tower is not used as a starting or early game helper.
Not a good tower, especially for Banana Farm fans. In BMC, I use 0/0, 1/0, 2/1, 2/2, 3/1 or 3/2 spam in Tiles and always get No Lives Lost. However I seldom use Ray of Doom because of its cost, I use 2/4 instead. In BTD5 and BTDB, this tower is useless.
Not a good tower. According to the table I made, this tower is totally useless in any games. However, in BMC, this tower has high popping power and they can be used to decrease the pops of other towers. Ground Zero is useless unless you are playing the MOAB Madness Special Mission, which using this upgrade is the easiest strategy. Spectres are still fairly good but too expensive. A lot of towers like Spiked Mines can replace this tower.
Excellent tower overall. In BMC, this tower is awesome if there is water. I use this tower in Contested Territory when there is water. Upgrading to Monkey Pirates in Contested Territory is very useful in late rounds to destroy DDTs and BFBs fully. It also has a specific use. In Bloonarius Boss Battles, spamming 0/1 buccaneers can be extremely useful in any levels. It can also be used to destroy a whole BFB sent by the Bloonarius using the Monkey Pirates ability. When you have enough money, sell the buccaneers but then upgrade one to Aircraft Carrier and cooperating with an Overclock can be really useful. In BTD5, this tower can be really useful too in water tracks. In late game, they are awesome as they can take down MOAB-class bloons fully where bloons' health increase and are much harder to pop, not that useful early though. In BTDB, this tower is one of the most important towers in water-rich tracks like Water Hazard. In Defend Mode, it can be a good starting tower in 00:54 after the $1000 +70 boost. The Grape Shot upgrade early is OP. In late game, this tower can be upgraded to Monkey Pirates to take down MOAB-class bloons fully as same as in BTD5. In Assault Mode, this tower can be upgraded to Grape Shot, Cannon Ship or Monkey Pirates too to help other towers. They can also be individuals to pop bloons themselves when upgrade to Grape Shot with some anti-lead support.
I love spikes, but not Road Spikes. It is not worth the cost. I only use it when emergency. However Road Spike Farming can be really useful but it is not encouraged using because of the huge Monkey Money input.
I like it too, I have more than 700 for free. I use it when emergency when I use up all Pineapples. Or, when I am playing Monkey Teams event, and Road Spikes are not allowed, I will use this instead of them.
BTD5 is a easy game overall. However, there are no necessary strategies for this game. So, I will only give some tips and you may find them useful.
If you are playing in a easy track like Park Path, you can simply use a Ninja Monkey as a starting tower. Remember to place it in a good place. For example, don't put it in the end of the track. Put it somewhere like a place where it can reach both the start and the middle of the track, or in a U-bend where the its range just reaches the middle part of the "U". (Note: If you are playing tracks with water, try using Monkey Subs by upgrading them to Barbed Darts, Twin Darts, Airburst Darts then Advanced Intel, then buy a new one and do the same. Keep doing this. It is a great strategy with a Bomb Tower support.)
If you are playing in Advanced or Expert Tracks with a lot of exits, you can use few Dart Monkeys separately. You also need to care about Cash, farming is a good choice. But you shouldn't be too greedy or your chance of losing is high. You need separate bomb support or a Full Metal JacketSniper Monkey in round 30 to pop Leads.
I can't help you with Daily Challenges. It is because they are different in every time. However, you can still message me on my wall for some tips.
If you are an expert or already has a well developed city, you should unlock Spiked Mines and promote Spike Factories. They are awesome in capturing Tiles with only one exit. You should also get Monkey Villages to help your costs of the towers.
If you are City Level +35, it means your city is really "Urban Developed". You should be capturing mostly Tiles above BFB. In this case, try to unlock more strong upgrades like Spike Storm.