Tip to easily win with tons of cash to spare: create a bottleneck shaped form leaving the middle open. Soldiers will go towards it and get slaughterd. Placing the machinegun behind also helps a lot. Ordinary cannon arent worth it imo
hm definatly something wrong with lvl 9, blocks getting stuck half the time, and now i've finished it perfectly, timer starts running but then stops for no reason -.-'