Godlike?
TLDR? Great game, needs some slight improvements.
Someone said that the game is about stress relief and I'd have to agree, seeing as it becomes glaringly apparent that the character isn't even mortal after about the tenth round.
At first the game was mediocre/hard in difficulty, with lots of emphasis on decision-making between rounds, choosing when to save and when to buy, which weapon to buy and whether or not to bother with upgrades. There were some weapons that were absolutely worthless because of other weapons sold for the same price offering equal and better stats.
The problems come in once the player gets weapons like the Desert Eagle (30 rounds? How large is the handle on that thing?) and the 999 shot machine gun, as well as the ridiculous shotguns. At that point the game loses all difficulty, seeing as even if the government were to decide to nuke the general area, the character would, in all likelihood, survive anyway with his monstrous 10k+ health.
There are also a couple flaws in the game, such as zombies not being able to attack you at all. I decided at one point to test my godhood only to find that the zombies weren't even landing attacks half the time.
Suggestions for future games would be to include some sort of boss battle, a better scaling on the difficulty and more variety with the zombies (not just continual recolors).
Finally, to compare with Last Stand, the games are in my opinion on equal footing. Each brings something unique to the table and neither was more fun to play or had more replay value.