There are lots of “games” out there about solving equations, but I haven’t found a single one that is more than algebra homework dressed up with pretty packaging. The “games” are all of the same format. We’ll give you problems, you give us answers and we’ll reward you (or your character) if you get them right. These are not teaching games, these are just more of the same kind of practice that you would find in an algebra text.
There is one applet that is worthy of mention, though. The Algebra Balance Scales from the National Library of Virtual Manipulatives is quite good. It isn’t billed as a game, but when you’re using it, you feel like you are playing a game because you’re interacting with the algebra on the screen. Unfortunately, this site no longer works without a Java installation, so if you want to still use it elsewhere, you can find a reincarnation of it on Hoodamath called Algebra Balance Equations.
An interesting assignment for an online or hybrid class would be to have the students record an example explaining the process and turn in the link.