What "best" means in IGTAP
There is no official tier list for IGTAP upgrades, and any page claiming exact price-to-value ratios would be guessing — kiosk costs scale as you buy, and the right purchase always depends on which part of your production is currently the bottleneck. What we can do is rank upgrade families by how strongly they compound, based on the mechanics shown in the official screenshots and confirmed by community playthroughs.
The core formula is simple. Your watts come from course completions, and each completion pays the base reward multiplied through the clone reward multiplier, while your completions-per-minute come from clone count, clone speed tiers, and your recorded best time. Upgrades that multiply several of those factors at once — or that apply to every course you own — are the ones that pay off hardest.
Best early payoffs: base reward and +Clones
Early on, the two kiosks that matter most are base reward (Xx base reward, +1x per use) and +Clones (+1 per use). A fresh course pays tiny amounts — the official course ONE screenshot shows a 2w reward with a Clone reward mult of 0.1x — so the fastest way out of the starting grind is to alternate between raising the payout and adding bodies to collect it.
Both scale linearly and cheaply at first, and they feed each other: more clones earn more watts per minute, which funds more base reward, which makes every clone more valuable. Community playthroughs of the early game show exactly this loop, with players ping-ponging between the two kiosks until an ability unlock (usually the wall jump) becomes affordable.
The one caution: base reward only helps the course you buy it at. If your income has already shifted to a newer, richer course, dumping watts into an old course's base reward is usually wasted — that is what global upgrades are for.
Best multiplier: clone reward multiplier
Once clones are actually running a course, the clone reward multiplier (+0.1 per use) becomes the strongest kiosk in the row. It multiplies what every clone on that course keeps per completion, so its value grows with clone count — a course with dozens of fast clones turns each +0.1 into a massive watts-per-minute swing.
This is the classic incremental-game trap in reverse: the multiplier looks underwhelming when you have two clones and essential when you have fifty. Buy it when clone count and speed are already decent, and its payoff dwarfs another +1 clone.
The multiplier pairs especially well with the chance-based tier upgrades below, since bigger, faster clones each run the route more times per minute and every completion is worth more.
Best global purchases
Global upgrades are the best watts-per-watt in the game whenever you can afford them, because they touch every course you have ever set up.
- Boost all previous courses — raises the payout of all earlier courses at once. As seen in the official screenshot it costs 1.20Pw, which is exactly the point: it is a late-game purchase, but by then your old courses would otherwise be dead weight. Community players describe the income jump after buying it as one of the biggest in the run.
- Maximum clone size tier [Global] and +1 maximum clone speed tier [Global] — these raise the ceiling for the chance-based tier rolls on every course. The speed-tier statue kiosk costs 475.47Mw as seen in the official screenshot. Higher maximum tiers mean your chance upgrades can keep paying off forever instead of capping out.
- Awaken the statue's power (11.09Gw as seen in the official screenshot) — a one-shot progression purchase that community playthroughs report boosts all previous courses. Few purchases change your income curve as sharply.
- Secret upgrades — found by exploring rather than bought at kiosks, and reported in community playthroughs to include permanent global watt bonuses. Since many are free once you can reach them, their value per watt spent is effectively infinite. Finding all of them is the Definitely not lost achievement, held by only 1.1% of players.
Best non-kiosk upgrade: movement abilities
The single highest-return "upgrade" in IGTAP is not a kiosk at all — it is a movement ability. Wall jump, dash, double jump, polarity swap, teleporters, zip movers, and the omni-dash each cut seconds off your best times, and because clones replay your route at your best time, every second you shave multiplies across every clone, forever.
A dash that turns a 17-second course into a 12-second course raises that course's completion rate by roughly a third for every clone on it, permanently, with no further watt cost. Community speedrun-minded players lean on this heavily: better platforming tech is literally better idle income.
Abilities also unlock the areas where the best global upgrades and secrets are hidden, so saving for the next ability almost always beats another round of kiosk purchases. The thumbnail below is from a community video built entirely around this clone-abuse loop.
Chance upgrades: strong late, weak early
The two chance kiosks — clone speed tier chance and clone size tier chance (both +6% per use) — are the most misunderstood upgrades in the game. Each purchase adds percent chance for a clone to increase its tier when it spawns, so their value depends on two things: how many clones you have spawning, and how high the global maximum tiers are.
With three clones and a low tier ceiling, they do little. With a large clone army and several global tier increases purchased, they approach guaranteed high-tier spawns and become enormous. The practical rule: buy globals and abilities first, then pour watts into chance upgrades once your clone counts justify them.
Size tiers in particular are opaque — even experienced demo players admitted they could not tell what a size increase did — but community observation of the full game shows larger clones paying out noticeably more per completion, which is why the maximum size tier global is worth raising early enough to matter.
Best endgame investments
Once watts are trivial, the best upgrades change currency entirely. The atom kiosk Turn all of your power into new atoms (276.51Kgp as seen in the official screenshot) starts the prestige loop tracked by the I am igtapic. achievement, and the upgrade tree — planted with Exponential growth, fully grown for Environmental Energy, a 6.8% completion achievement — offers the deepest global bonuses in the game.
Refresh orbs, unlocked by the Stem Cells achievement, add another layer of late-game power for active players. None of these have published cost curves, so treat them as directional: whenever your next atom or tree node is within reach, it will outperform any remaining watt kiosk.
The summary principle for the whole game: buy what unblocks your current bottleneck — payout early, multipliers mid, globals and abilities whenever affordable, and prestige resources the moment they open up. For a concrete step-by-step sequence, see the upgrade order guide.