Good, but nowhere near great
It's a decent game, with the makings of a very good game, but it's so unbalanced that it's not very challenging, and so not very fun. The computer alternates between dropping missiles on your team with pinpoint precision from across the map and firing them into a mountain point-blank. There's also not any real sense of purpose: the initial rank goals seem sort of pointless when you can set up a game to guarantee a 1P win, and you're all but guaranteed to end up playing yourself for the 2P win. For an alternative mission structure, look at "Territories", a similar submission.
In general, the weapons seem overpowered: there's little reason to not use a missile when you can walk a few steps away and then blow a quarter of the screen up. The grenades seem sort of redundant: either tone down the missiles to require a near-direct hit, or replace one of them with a gun-type weapon.
Again, you've got everything you need for a great game, you just need to put it together differently.