I think I'm going to have to give Intrusion 2 a pass. I mean no disrespect if you like it, but it's just not for me.
I'm pretty bad at all things Contra-like. Intrusion 2 reminds me more of Contra than it does Metal Slug, despite containing vehicles. There are nice ideas spread throughout and you don't often see physics in a game like this, but some... interesting control decisions and the perpetual shaking of the sprites are a turn off to me.
I started play with a 360 pad plugged in. Navigating the menu using the pad crashed the game. I retried using the mouse to navigate the menu and successfully entered a game. This is basically Megaman (in the same way that CoD and Battlefield are Doom), so it should be pretty good at run, jump, 'n' shoot. Running and jumping are pretty easy, though I would prefer if jumping was mapped to something other than up. Shooting, however... You aim with the right stick and shoot with one of A or X, but I forget which. Since you constantly need to aim, the control system doesn't exactly make it easy to shoot what you're aiming at.
I switched to keyboard and mouse and played until I got a wolf. You can still run, jump, and shoot, but only in the direction that you're aiming. If you want to run away from something while firing at it, you get to watch the wolf slowly hop backward a few pixels at a time.
A combination of the prior issues and my own incompetence leading to a dislike of the genre mean I will probably never finish this game. I can't really recommend it to anyone who doesn't love the genre.
That's too bad, I think it may be the best run and jump shooter I've ever played, but it's physics based controls are a bit clunky, and it's definitely not designed for a controller. However I think you're a bit quick to call it only for lovers of the genre. It really starts to shine after the first level as you get access to better weapons and fight the absolutely amazing bosses, and it's low difficulty option make it something I think even someone with a very casual interest in the genre could enjoy.
Thanks for the vote of confidence, EuchreJack. I was pondering closing the challenge just now as it's starting to turn into "Mephisto plays and reviews his Steam library but doesn't actually finish anything." I'll continue as long as people don't find this annoying.
I'm going to keep going as well, but I'm going to be playing exclusively RPGs, so I'm aiming to finish one a month.