It's very difficult, however. I'd go for about 20 melee soldiers, 40 worker tanks built up early to collect food, 40 workers doing nest work, and 60 spitters (rapid-fire for high-end PCs, mortars for low-end PCs). All other food should be used for reinforcements on the last day.
The significant nerf to lvl 3 mortar splash damage has made the cost of making them far too high to opt for it. Lvl 1 spam is now the only way to beat 2.2, and will probably leave you heavily constrained in terms of food. Typically, most food is spent gaining numbers, but here the reinforcements will have costs ranging from 500 to 2k in a single day.
Do your best not to over-spend, and make no attempts to kill enemies on the lower levels.
The significant nerf to lvl 3 mortar splash damage has made the cost of making them far too high to opt for it. Lvl 1 spam is now the only way to beat 2.2, and will probably leave you heavily constrained in terms of food. Typically, most food is spent gaining numbers, but here the reinforcements will have costs ranging from 500 to 2k in a single day.
Do your best not to over-spend, and make no attempts to kill enemies on the lower levels.