Downwell

Area 1 is The Caverns. Shops have the cheapest prices, and enemies do not pose much of a threat. Enemies consist of eyes, snails and crawlers, which you need to shoot to kill, and worms, bad bubbles, bats, turtles and frogs, which you can stomp.

You can build higher combos here, and try to get at least the 15-hit variant, so you will increase your clip. Also, search every cavern, and try to kill every enemy, as you need gems to buy clips/health from shops, and to unlock styles.

The trophy will unlock at the upgrade selection screen of Area 1-3.