Anura - 5
Capture a frog with its tongue fully extended.
This can be done on any difficulty but just stick with Easy. Frogs are one of the enemies you have to purge from the rooms. Their pattern is they hop once then extend their tongues. Then they turn and hop again and so on. Wait until only frogs are in the room as it is easy to judge where they will go and you can avoid them. When a frog is extending their tongue make a circle around that frog. If done correctly the achievement will pop as soon as the frog is captured. Watch out though! Touching their tongues will cause you to lose a life.
Banish - 5
Capture 5 or more enemies in a single vortex.
This will probably be your first achievement you get. Simply create a vortex around 5 or more enemies to capture them. Aside from the first few rooms on Easy mode every room will have at least 5 enemies.
Easy Street Millionaire - 15
Score 1,000,000 or more points on Easy difficulty.
Start up a game on Easy difficulty and start purging the souls from the corridors in each room. As stated in the Roadmap you can go through the levels and rooms as many times as you wish as long as you keep surviving. You start out with 3 lives but as you destroy enemies they release blue spheres that you collect. When enough have been collected you gain another life. I had around 11 the whole time through Easy and I had to pass through the game about 1.5 times before I got to 1,000,000 points. Remember to create a vortex that engulfs the ENTIRE room when enemies are spawning to easily kill everything at once.
Exorcist - 20
Capture 30 or more enemies in a single vortex.
Based on the points you earn for this it may seem difficult but it is not. Easily obtained on Normal/Hard mode if you want it quickly. It can be obtained on Easy mode but you have to wait for the later levels (about 15 minutes into a game) before enough enemies spawn to even attempt this. As stated in the above achievement just circle the entire room to create a huge vortex and it will suck any and all spawning enemies in. On Normal/Hard mode this will unlock fairly early if you use this method. It will pop as soon as 30 enemies have gone into your vortex.
Exterminator - 10
Capture 15 or more enemies in a single vortex.
Just like Banish or Exorcist but only requires 15. This will probably be your second achievement you unlock and is easily obtained while going for Easy Street Millionaire. Practice the same plan of engulfing as large of an area as you can with your vortex and you will have this one in no time.
Extreme Street Millionaire- 50
Score 10,000,000 or more points on Hard difficulty.
This may seem difficult at first and will be the hardest achievement but with a little practice of timing your vortexes and patience this achievement is a piece of cake! More enemies spawn on Hard difficulty and it seemed to me it took a little bit longer to gain lives from collecting blue orbs. Don't let the scoring fool you either. Enemies are worth more as the difficulty increases so it won't take you long to get this achievement if you are patient and time your vortex correctly. If it seems like a tight fit to make a vortex just hang back and wait. Also making small vortex as you run from/dodge enemies can take out a few wandering enemies. Every little bit helps! Just keep at it and you will get this achievement in no time.
It's a Trap! - 5
Create a vortex that encircles no enemies, but captures 5 or more.
I got this accidentally during Easy mode but once you know how enemies behave it's a snap! Just wait until either the white rats or the golden flying beetles appear. They follow you wherever you go. Go to one side of the room with at least 5 of them following you. When they have almost cornered you fly to the opposite side and place a large vortex. They should follow you and fly/walk right into your vortex. The achievement will pop as soon as this happens.