Yeah, it looks like a single bomb does the job too.
1~w_i:368.35,360|w_i:408.25,361.7|w_i:450,361.65|w_i:489.9,361.65|w_i:493.3,238.35|w_i:388.25,179.95|w_i:451.65,236.65|w_i:471.65,301.65|w_i:388.25,300|w_i:429.9,303.35|w_i:368.35,236.7|w_i:408.25,238.35|ws_i:388.25,391.7|ws_i:430,395|ws_i:471.65,393.25|w_i:430,180|w_i:471.65,178.35|w_i:368.25,113.3|w_i:408.35,116.65|w_i:450.05,113.3|w_i:493.35,115|w_i:388.35,55|w_i:430,58.3|w_i:471.65,55|w_i:368.35,-10|w_i:408.35,-6.7|w_i:450,-11.7|w_i:493.35,-10|w_i:390,-66.65|w_i:430,-63.3|w_i:471.7,-68.35|w_i:370,-131.7|w_i:408.35,-130|w_i:449.9,-133.35|w_i:940,-131.7|w_i:493.35,-133.3|fl_i:461.55,-201.65|fl_i:440,-338.35|fl_i:654.9,-213.35|w_i:370,-271.7|w_i:391.7,-271.65|w_i:413.35,-271.65|w_i:435,-271.7|w_i:455,-271.7|w_i:476.65,-271.65|w_i:495,-271.65|p_t:380,-368.3|p_t:500.05,-366.65|fl_i:850.05,-201.6|ws_i:390.05,-158.35|ws_i:430,-155|ws_i:918.35,-163.35|ws_i:470,-161.65|ws_i:875,-163.35|ws_i:833.35,-163.3|w_i:896.7,-131.7|w_i:853.35,-130|w_i:813.35,-131.65|w_i:833.35,-70.05|w_i:875,-70|w_i:918.35,-70|w_i:940,-6.7|w_i:896.7,-6.7|w_i:855,-4.95|w_i:813.35,-6.7|w_i:835.05,54.95|w_i:875,53.35|w_i:918.35,54.95|w_i:940,118.3|w_i:896.7,118.3|w_i:855.05,118.35|w_i:813.35,118.3|w_i:833.35,178.35|w_i:875,176.7|w_i:918.35,178.35|w_i:940.05,243.3|w_i:896.65,243.3|w_i:855,243.3|w_i:813.4,243.35|w_i:835,303.25|w_i:876.7,301.65|w_i:918.35,303.35|w_i:940,368.35|w_i:896.7,366.7|w_i:855,368.35|w_i:813.35,368.25|ws_i:833.4,395.05|ws_i:875,395|ws_i:918.35,396.7|w_i:941.7,-268.3|w_i:920,-268.3|w_i:898.4,-268.4|w_i:876.65,-268.35|w_i:855.05,-268.35|w_i:833.3,-268.35|w_i:811.7,-268.35|fl_i:875,-335|p_t:815,-365|p_t:935,-365|p_t:593.35,-243.35|p_t:685.05,-245|p_t:623.4,-321.65|p_t:638.35,-396.7|w_s:555,358.35|fl_s:643.35,286.65|w_s:730,356.65|c_s:558.35,246.65|c_s:766.7,381.65|c_n:518.35,385|c_n:333.25,383.35|c_p:590,380|c_p:638.35,381.65|c_p:685,383.35|w_s:586.65,220|w_s:728.35,220|fl_s:640,149.9|c_p:623.4,243.3|c_p:673.35,245|w_s:585,81.65|w_s:726.7,81.6|fl_s:638.35,10|c_k:621.7,110|c_q:681.7,108.3|p_c:548.35,-20.05|p_c:548.35,120|c_s:585,-30|c_s:625,-31.7|c_s:660.05,-30.05|c_s:703.35,-30|
That one can stand against a single bomb, but a triple bomb takes it down immediately. But one princess stayed alive for a while even after the walls fall. I found that if the princess on the bottom right survives the walls crumbling, the walls will fall so that you can't get her. You have to beat the level in one shot. (I have beat it, but only once).