@EvilGM there is almost no time management in this game. It's much more of a resource management game. And if you don't like it, don't play it. Why whine about it?
The mechanic of collecting stuff off the ground is annoying, and I don't see how i adds anything to the game. Everything other than that is pretty much brilliant.
Today's challenge is lulz. I kept going after it was done simply out of curiosity. I'm now on wave 95, the whole map is just filthy with glaive lords, it looks like a Cuisinart from hell, and I'm still waiting for something to get past the first U bend.
25/9 - you don't actually need the freeze towers to beat today's challenge. There might be a more elegant strategy than mine, but I just started with three tack towers over the first few rounds and then just started throwing dartlings at the problem. Worked like a charm.
9/23 - For today's challenge I used 1 Ice tower upgraded to 2/1 form the beginning, 3 ninjas, 1 speed sniper and 1 power sniper (this one fully upgraded by the end) both set to "strong." upgrade the speedy one first. Hope this helps.
9/20 - For today's challenge start with a mortar and a buccaneer upgraded to destroyer. Get a dartling gun next, get the cheap upgrades for that and the mortar, then get a second gatling. get the first 3 upgrades for that as well, and then a super monkey. Upgrade as you see fit. Use the monkey storm against the lead camo bloons. everything else is cake.
 "Jacksmith")
 "Bloons TD 5")
 "Pheus and Mor")
 "Kingdom Rush")
 "Cloudstone")