This is a return of an old classical 2 players game. This is not a new remake. As I noticed they changed only three things:
1. Added a filter that makes pixels look smoother. Can be disabled, but I really liked it (steam store screenshots have it turned on).
2. Added autosave of the last unlocked password. No need to write them down on a sheet of paper. Handy.
3. Not only local, but also a network multiplayer (2 players coop campaign).
None of these features really make this game better or worser than it was before. I hightly recommend it to those who played this game years ago and liked it. It's still the very same fun game. On the other hand, mashing Fire is still a need as this way you shoot faster than if you just hold Fire key/button.
For those of you who didn't... Well, it's a good 2 players coop game, played good if using the same computer (keyboard or controller for each player). The game is of average difficulty. It can kill you really quick if you are careless, but not unbeatable and doesn't require super reaction or precision. No combos, dirty tricks, you can play it straight out of the box. A lot of guessing elements appear later in the game and make you life easier or harder depending on your choices. This game will not take much time, it has autosave every half an hour or an hour at later stages when you reach a new world.. or if you loose all your lives before that :D. If everything goes good, you'll be able to complete it in one go in somehting like 3-4 hours. Six different characters and different special power (unlocked later) give this game some replayability, but not too much. Finishing it 1-3 times will probably be enough for most players.
If this sounds fun - you should try it. If not - pass by, this game is quite good, but not a must see.