Pro:
- ♥♥♥♥♥♥♥♥♥ of stuff to unlock
- Fun and fast to understand gameplay
- Upgrade and XP system to level up towers
- weekly tournaments PvE for fastest times or highest rounds
- daily stacking rewards

Con:
- Mini transactions and buyable stuff everywhere
- shops gets really expensive fast
- multiple currencies to extend the grind even more

for time killer

Cute little tower defense, the build your own path is a neat idea.