I always had an idea about exponencial growth, and I remembered right now. It would solve this mantaining the essence.
Let's say there are 10 levels (think about levels, number of upgrades, total cost of them, etc). So you need...
- 10 exp to lvl2.
- 20 exp to lvl3.
- 30 exp to lvl4.
- 50 exp to lvl5.
- 80 exp to lvl6.
(Fibonacci, where?)
- 300 exp to lvl7.
- 1.000 exp to lvl8.
- 10.000 exp to lvl9.
- 9.999.999 exp to lvl10.
Voilá! You'll groth as usual. When you reach lvl6, you are kinda strong. Then, you need an extra effort to get lvl7. Then you see lvl8. Damn, hell, a bit of hard now. Still affordable. Alright, I'm lvl8. EIGHT FROM TEN, its 80%. I'm super strong... but hey, I can reach 9. DAMN HELL, TEN TIMES MORE. Ufff... that's difficult, but... hey, I think i can get to it with effort and time. HELL YEAH, I'm 9... ow ****. OW DAMN ****. THIS MUST BE A FCKNG JOKE. But hey. I'm level 9. I'm at 90% of my power. That's a lot. I'm SUPER STRONG. I can get almost everything, try almost everything, this is so much fun, I feel my effort has been rewarded. I could quit right now and be satisfied but... WAIT... If I continue playing for A LOT of time, I'll get exp to get to 10 someday... and I won't feel those extra points wasted, just an step towards perfection someday.
That's what I think. That was the idea some day I get to, and I would use in my hypothetical game