Tip 1: Upgrading gems is intrinsically cheaper than buying new ones, just make sure you have 80 mana left over after purchase otherwise you won't be able to combine them.

Tip 2: Upgrading your maximum mana and spell cost is a must-have if you want to be able to play around with the higher-level gems.

Tip 3: Orange gems are the baseline tower weapon, but the harder waves are often best served by upping your critical chance or employing a bounce gem for the larger, quicker groups.

Tip 4: Poison, stun, and slow traps are lifesavers and should be placed down fairly early.