User blog comment:Sam Wang/BTD5 - Tips For Reaching High Rounds/@comment-3153244-20120808070404/@comment-4316832-20120808095417

Altha is recommending Ray of Dooms, whilst you are saying it's on the down side. One possible way for the one I'm doing currently now is possibly to sell the ray of dooms close to the track, and then upgrade them to MOAB Assassins. Whilst keeping the ray of dooms far from the track.