Here's what I've figured out as far as high level strategy:
Working backwards, you want to get a boss to max level (3b) as soon as possible. To pay for that, you want to get a generator to max level (200m), with the highest value. To max the value, you surround it with 4 task masters, but you need to max the level of the task masters (since they will contribute their own value). The best way to raise the value of the task masters is with leaders.
Here's a more detailed walkthrough of what I do:
Optimal start is generator, upgrade, generator, upgrade, leech. I'm not sure what is optimal after that, but I generally play something like the following to get started. I place a "base" generator in the top left and build off that. Almost all of these other tiles will be replaced though.
After about $40/cycle, I will place one or two catalysts around the "base" generator in the top left. Then it's a slow process to place leeches and upgrade to max level, and place two more catalysts.
I build out the rest of the board, placing max level leeches and adding 5 leaders. 5 seems to be a good balance for cost. Once the board is filled it looks like
The next step is replace the catalysts with taskmasters.
After all four task masters are in place, then I upgrade the leaders to max level (5m).
Then wait, wait, wait for 200m to max the generator (this is two or three minutes of doing nothing). "good" numbers seem to be, you want to have $200m around $1.92m/cycle, and that will jump your income to 8-10m/cycle.
Then place a single boss (20m) (replace any leech), upgrade (50m), and wait, wait, wait for 3b for the final boss upgrade. The game is essentially over at this point, but you have to wait for the boss to double enough. You can speed it up by a minute or two by placing as many other bosses as you can and upgrading to max level (this is what enabled me to finally get sub 24). This is because they normally tick once/5, so if you can stack multiple it will grow much faster.
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Things I'm not sure about:
Generators should generally be upgraded as soon as possible, probably.
The end game seems to only require one generator, due to the growth from the task masters, but it seems like you should probably start with more than one generator, to have multiple low level leeches. I generally have the "base" generator in the top left, but I have a secondary generator in the lower right with catalysts that get upgraded to leaders. This seems like it has room for improvement ....
A leader adds +1 to every square on the board, which is +25 by itself. Each max leach will add +25 to that. This is base every 5 ticks, so I'm not sure if it's better to upgrade these first, or if it's better to place task masters first.
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Overall this is a fun game, I've probably spent around 20 hours playing, would recommend.