Oh yeah, steep learning curve. No wait, that's not a curve. That's a really decent game ruined by one impossible boss :| good game but the difficultly needs improvement!
Use boiler to get a special word (usually E), use the word of the day (PREMONISH) around level 5 with about 4 of the letters (PrEMOniSh) and you'll get just over 100. I got 109. Enough for me :)
The achievements get a bit tiresome. 1500 kills etc. Would rather have more than 3 different types of level than grinding the same thing over and over. 3/5