cant pass lvl 1 stupid towers

The 20% build discount perk doesn't work for both the Cannoner or the Gunmen towers. Please fix

... to recommend this game. Going to play a little more before I post a review, but there has been nothing really interesting or fun yet. A lot of the assets seem, shall we say 'borrowed', even the maps feel familiar. The towers are so vanilla they are a major step down from the minimum expectations. They all seem to do the same damage and have the same range, only the rate of fire changes with the cost. If any of them do anything interesting, like a slow attack or an AoE attack, it isn't mentioned in the ...

I am completed up to levels 8 & 9 hardest level - what is the incentive to use any tower other than the Arrow Tower and its upgrades, or am I missing something??