Can A Game Be "unhackable"

[ST0RMPEGASIS]

My question isn't if hacking is illegal or impossible to spot but if it's impossible for some games. By hacking I mean a mod or modification which grants the users advantages often physical in games. Is there a flash game or unity game which can't be hacked. Experimenting for a while with certain game hacks I found out most of the hacks were only client-side, I assumed that technically a host with super internet can cause everything even the graphics server side only. What do you think about cheating a game are there any unhackable games or not?

[flashgamehacker]

No there isn't a Flash or Unity game that cannot be hacked

Both of these types of games are client side games so the games source code can be altered and changed with cheats. There are protection schemes for flash to make this harder but 99% of them can be defeated easily

Server side games cannot be hacked in the same way. Clash of Clans for example is a server side game and so all items etc. are generated by the server and then sent to you not the other way around and so there is no way to change these.
Some server side games can still be cheated by intercepting the server requests and changing them or auto bots can auto play with the server to generate items

[tmanzz122]

We make the game Local-Only. We literally cut the game off from connecting to leaderboards, servers, and what not. We don't touch Server Side.

As for unhackable, that is non-existent unless encryption gets ahold of itself and everything gets AES-128 or better. So, no everything is hackable.

[ChaoticCHAOS99]

everything is hackable.

Not everything.The big games out there are heavily encrypted and some have firewalls. Breaking through the firewalls is illegal so in a sense its unhackable.