You're a little knight. You've had your worst knightmares confirmed; yes, you're inside a computer game. And, horror of horrors, it's a platform game. Time to escape, you might think. And you wouldn't be wrong. That'll do for plot, as it's completely and utterly wrong, but the real one isn't much better. Erik is simply a platform game. You must fire crossbow bolts (or something like them) at the bubbles which get in your way, as well as leaping from platform to, erm... what was it? Never mind. It's a pretty cute game, marred only by the rather distant feel of the character.
This is quite important because the chap must be positioned perfectly for many of the jumps. It's one of those annoying pixel-perfect jobs, and when you get it slightly wrong you will curse and howl like Peter Cushing in that film on telly the other day. The sound effects are good, though. So good that you turn the volume up. Then you turn it back down again because you're getting annoyed with not being allowed even the smallest leeway when hurling yourself around the level.
Buy Erik if you're a smartass and reckon all platform games are dead easy.