Five fronts, five masks. Push each one back tier by tier, break its ten Hells, and the next front opens.
Choose a bonus
The front is clear. Keep going into endless tiers, or go home with your earnings.
Get both attacks to Lv.3 in a run. The fusion then always shows up as a choice. It takes one slot and replaces both.
Each attack earns Mastery from its share of the damage in your runs (more for higher tiers and Hell). Spend Mastery + scrap + medals to evolve it. Fusions use the higher tier of their two parts.
Moving. Drag anywhere (or WASD). Your attacks fire by themselves.
Tiers. Kills fill the tier bar. Clear a tier and pick a bonus. Bosses (tiers 5, 10, 15...) must die before you move on. After 60 s with a boss, the gas rolls in.
Attacks. 6 slots, levels 1 to 5. Each level-up card lists exactly what that level adds (more damage, plus things like extra bullets, pierce or a bigger area).
Fusions. Some attack pairs fuse when both are Lv.3+. You have to find them. A fusion takes one slot and replaces both.
Ascended and Apex. Two fusions that share no attack can fuse again when both are Lv.3+ (ASCENDED, x1.5 damage), and two Ascended into an APEX (x1.8 on top). Every part keeps firing inside it.
Tiers. 44 tiers and 14 bosses a run. Each boss is its own half tier (Tier 3.5, 6.5 ...) and gives a bonus pick when it falls. From Hell I on, event tiers (real battles, wrecks and rushes) can show up between tiers with their own enemies and an item found nowhere else.
Levels. Kills give XP and every level costs the same, while XP per kill grows every tier: a run ends at levels in the millions, and on the last front in the trillions. Your Mask gives stats for every level.
Where it comes from. From tier 2, gas shells land near you every few seconds (a red dashed circle shows where, 1.5 s before). Gas troops leave a cloud when they die. Bosses and elite bombers drop gas too.
FILTER. In green gas your filter drains about 20 per second. Out of gas it refills 3 per second.
Empty filter. At 0 you lose 7% of your max HP every second you stay in gas. Step out!
Gas Seal slows the drain: at 80% (the max) it is about 10 per second.
Nothing drops to heal you. No canisters, no med kits: your filter refills slowly out of the gas, and clearing a tier heals 10% of your HP.
Other fronts: Deep: ink drains your AIR; air hoses lowered from the ship refill it fast. Mine: firedamp drains your air, and fire IGNITES it (a blast that hurts enemies only); outside your lamp it is dark. Jamboree: dark patches drain POWER and make enemies faster; pools of light recharge you and slow them. Plague: miasma drains your HERBS; smoke rings clear it.
Fire from your attacks burns gas clouds away fast. Your own poison is blue and never hurts you.
The gas rolls in. After 60 s against a boss the whole field counts as gas, and it gets worse every second. Kill bosses quickly.
Ordinary enemies only hurt you by touch. Only bosses and elites (purple-ringed) shoot or throw things.
Items. Purple-ringed enemies carry an item. You find out what it is when it drops.
On screen. Each enemy shows its HP and its damage per hit (before your DEF). Your stats are bottom left; pause for the full list.
HP is your life. At 0 you fall and the run ends.
ATK is the base damage of every attack. Each attack hits for ATK x its own power x its level.
DEF softens hits: you take hit x hit / (hit + DEF). DEF equal to the hit halves it. Every hit still takes at least 2% of your max HP.
LCK makes rarer bonus cards. It never changes item drops.
DPS is your damage per second over the last 5 seconds. Pause shows it per attack.
Crit is the chance a hit crits (5% to start, max 100%). Crit DMG is how hard: 150% to start.
Atk Speed makes attacks fire more often: +100% = twice as often (max +400%).
Size makes blasts, auras and clouds bigger. Projectile adds shots or blades to most attacks (max +10).
Duration makes clouds, turrets and other lasting things last longer.
Resist cuts damage again after DEF (max 80%).
Regen heals that much HP each second. Lifesteal heals a share of the damage you deal: at most 4% in the whole game (one Field Manual upgrade on page 26 and one item give 1% each), and at most 0.5% of max HP per hit.
Move is your speed (max +150%).
Filter is how much gas you can breathe. Gas Seal makes it drain slower (max 80%).
XP, Medals, Scrap give more of each.
Loot raises every item's drop chance (Loot +100% = twice as likely).
Medals come from clearing tiers and bosses. They buy upgrades in the FIELD MANUAL. Spend half of a page to open the next. Every 4th page is a supplies page with big flat stats.
Scrap comes from kills. It buys gear from the QUARTERMASTER. Gear never changes.
KIT. Wear a Mask (stats every run level), Arms, Uniform and Kit items.
Orders are one-time goals with rewards. Field pay earns medals while you are away.