There is a bug with auto reboteer. if you are holding crystal at the time it prestige you can carry the crystal into the new prestige. Also i am at batt 12 and passives menu has not opened yet.
best td i have seen in some time its challenging and gives u a good (not great) amount of freedom on how solve the level given the tower selection and resettable upgrades. It could use some more polish though. For example 2% across the board (-health) for upgrades, could be balanced better. On lv 5 i noticed guns don't always fire (think the ai is targeting enemies that it can't hit due to the walls but that's just a guess). The info menu could use some expanding, it would be nice to see some numbers for fire rate, damage and such for the different tower lvs instead of learning through playing. 4/5 as the game is. Something i would like to see but would most likely be a real pain to implement and balance is a choice of specialized towers after upgrading a tower to a certain lv.
The effects really give a nice feeling to the game. Towers are over powered though, smaller range or larger map compared to tower size might help. Creep diversity would be a big help to make it more interesting as well.
 "Block Fuser"){kind=icon}
 "Sheep Force"){kind=icon}
 "The Hero Business"){kind=icon}
 "Square Defender"){kind=icon}
 "CYBORG Tower Defense"){kind=icon}
 "Galactic Clicker"){kind=icon}
 "Defend the Keep"){kind=icon}
This was fixed in the last patch.