Well I'll probably carry it too far but here it comes:
1) I would replace the more money upgrade with two kinds of upgrades: One that increases the outcome of your upgrades but gets expensive much faster (exponentially) and another that reduces the time needed for your autoclicker bots (?) to produce (also exponentially)
2) Change the unlocked bots so they work differently. The first one should beless expensive but could increase with each upgrade the production linear while folowing bots get expensive more quickly, start lower but have a higher (again exponential) max outcome (Example: in the end the first bot generates 100.000 in 1/2 of a second while the 10th bot generates 10.000.000 in 1/10th of a second when fully upgraded)
3) Change the way you store the curency so that you can go to infinity and beyond (you could store an exponent of ten and just calculate the last 20 relevant digits)
4) MOAR BUTTONS :D
5) RESET button ("Prestige system"): Once you reach a specific goal you can reset and start anew with some kind of permanent and randomised ("+10% yield" bonus or "-5% on upgrades" or "+20% on clicks" or "+1.000 starting balance" or (rare) "+1 starting bot/upgrade" or (epic)(moaaar rare than before) "+1 level per bot once unlocked" or (legendary)(you guessed it MOOAR RARERERERERER) "+20 max bot level") combined with another goal more difficult to reach (could be hand-made or just randomised with (i like it) exponentially higher goals)
6) expensive cursor upgrades ("skins"), hidden until unlocked
7) Some easter eggs (Example: When prestiged for the 10th time on red button press: Nuclear-weapon-gets-armed-alarm-sound)
8) Small congratulation once reached a certain point :)
You don't have to implement any of these things and if you do it could be best to upload it as a new game cause there would be some major changes...
Cheers, Sam ^^