There really should another planes to use and upgrades to the plane, like less stall, faster speeds, etcs. Machine guns should auto-reload, instead of having to fire the remaining bullets.
Knowledge boosters are bad coded. The boosts are only applied to previous values, they don't apply to the total if you upgrade a resource production after the boost.
Every game hour should give 1 Kred for spending in game. Also if you buy like a Lemon Stand, and if you already have a Manager, it should auto-start the progress.
Already have it going in my current build. The update will hopefully be out soon. ~Taiga