Items can be bought with the currency you collect from completing levels. A better end score means more money to spend but if you’re having trouble, you can always replay an earlier level to stock up. The items are bought at the shop which you can access between levels or from the main menu.

	Bombs explode in a radius big enough to catch a wave or two, provided you place them effectively. Unlike the other items, it takes a couple of seconds to activate, meaning you can’t just throw them down on top of enemies.
	Hammers repair the gate but the amount of health restored gets higher as the gate’s own gets lower. Do you save it until the health is really low or do you restore it at halfway so you can turn your attention elsewhere? It’s up to you to decide!
	Temporary Towers are short-lived mini-archer towers that can turn the tide of battle just when it’s turning bleak. While they build up quickly and don’t cost any gold or mana during the gamplay, they only last so long before they crumble back down again.
	Shrink Spells shrink the enemy down reducing not only their speed, but their damage as well. This can trap a horde of enemies in an area for longer meaning that your towers get more of a chance to pelt them before they get near your base. Casting it on enemies already attacking the objective means you might buy yourself a couple of precious seconds as well.
	Dispell Scrolls remove any buffs placed on enemies within the area which you cast it. Nothing’s scarier than a full horde of Brutes with toughness and strength buffs but using this item will revert their normal, slightly less intimidating state!

You can also check out the blog post about buffs here.