Crypt of the NecroDancer

Items to look out for:

Ring of Gold:
This is great if you get it early on, as I did, because you don't have to worry about destroying gold with your bombs. This means you'll have plenty of money for shops (I had ~1700 by the end). Once you have enough gold, you may want to swap for something more helpful.

Miner's Cap:
This really helps keep you from getting trapped by enemies, and speeds things up a lot.

Ring of Phasing:
I didn't get this on my run, but this may be the best item to get -- you can easily escape from enemies by walking through walls, and you can even plant bombs IN the wall to kill enemies! NOTE: this does nothing if you also have the Miner's Cap on, because the walls will get destroyed! But you can pick it up anyway, and hope to find a different helmet later.

Boots of Leaping:
These let you jump over a square, which can be very helpful to escape the faster enemies.

I recommend reading the wikia page for more tips: http://crypt-of-the-necrodancer.wikia.com/wiki/Eli

Bosses:
You may want to go into practice mode before trying for the achievement.

Heavy Metal:
This boss is surprisingly easy since you have unlimited bombs. Just kick a bunch at him until he's dead. Take out the smaller enemies if you have to.

Coral Riff:
My strategy was to drop a bomb immediately, and move left or right (don't wait for enemies to spawn, because you'll get hit). Enemies will usually spawn near you and your bomb will hit them. Once they start moving, kick or drop bombs and run.

Deep Blues:
Immediately kick bombs up and kill as many pieces as you can. Watch the left and right and kick bombs that way if anyone is getting close. If a pawn turns into a queen, drop a bomb and run away, since they can move quickly. Overall this shouldn't be too tough.

King Conga:
This was the hardest boss for me, because enemies can easily swarm you. I recommend hanging onto any spells that might help (earthquake, shield, freeze, etc.). I used a shield and just went crazy with bombs, then carefully killed the remaining enemies. Remember that King Conga can move diagonally, so drop bombs and run, don't kick.

Good luck!