Addictive game loop
Start a run, see how far you get. Use your collected resources to buy upgrades and try again. Become powerful enough to obliterate everything coming against you.
Deep upgrade tree
Create unique builds that fit your playstyle. Experimentation is rewarded, and all upgrades can be refunded for free.
Strategize
Focus on upgrading just one specific tower, or find unique tower synergies. There are many ways to progress through Outhold, the choice is up to you.