Progression

Este artículo está escrito en inglés.

A run ends, your profile stays. Experience, levels, skill points and saved strategies carry from one run to the next.

Levels and level rewards

Every run earns experience, and your player level decides which skill tree nodes you can buy. Levels also pay rewards of their own in solo:

• +$5 starting gold at levels 3, 5, 7, 10, then again at the same steps of every following group of 10 levels (13, 15, 17, 20 and so on), up to $80 in total.
• +6% tower damage (one Damage card's worth) every 10 levels, up to 5 times.

These rewards do not count as cards you picked, and they do not apply in multiplayer.

The skill tree

Bosses pay skill points. In solo you spend them between runs on permanent upgrades: every rank costs one point, and you can refund ranks at any time. This is where each tower's level-2 and level-3 upgrades are opened, along with bonuses for every tower, a bigger factory, a longer radar reach, extra rerolls and extra cards per offer. In multiplayer everyone starts from zero and spends points during the match instead.

Strategies

A strategy records your board: which tower went on which tile, in the order you built them. In a later run, activate it and the game spends your gold rebuilding that layout, one tower at a time, while a wave is running. It only fills empty tiles, skips towers you have not unlocked yet and never tears down what you placed. The Strategy+ skill adds more saved boards, up to 3.

Crystals

Clearing wave 50 on Nightmare drops a crystal into your Steam Inventory, once per account. A crystal is bound to one tower type and raises the damage of every tower of that type for the whole run, by 5% to 35% depending on its rarity. Only the best crystal per tower type counts, and crystals can be traded on the Steam Market.

Achievements and mods

The game's Steam achievements are listed on the achievements page. Mods that only change the looks play exactly like the vanilla game. Mods that change gameplay play on a separate profile of their own, and while one is active, experience, achievements, crystals and leaderboard scores are switched off.