I found Grappl rather entertaining, despite the lack of content. The sword attack mechanic was well implemented, and I appreciated the challenging level design. (Although, at times I thought it could use a slight bit more variety). The Grappling mechanics were solid, and although hard to control, were soundly coded and bug free.

On the other hand, the game does suffer from a lack of variety, in both visual aspects and gameplay. The levels, although well designed, appeared visually static (the fact that it is based within a training complex is no excuse). In terms of audio, the sound effects fit well and never grew tiresome, but the lack of music was a little disappointing.

In conclusion: Grappl, as it stands, is an entertaining game sporting a creative and engaging approach to combat, but it suffers from monotony, and although I enjoyed myself playing it, I could not excuse my disappointments.

extremely addicting

Lovely. I must say, though, it was rather difficult, because the grapple mechanics, while great, were quite hard to control.

Awesome game, great grapple mechanics, but it needs music D:

...You should be proud of yourself, buster – delivering some hard nostalgia to people isn’t really as easy as it seems to most newbie developers. Good old Worms\Liero times... Some remarks, however:
1) It should be indicated if hook can’t reach point under cursor without being affected by gravity. Better use custom mouse pointer and it’s color depending of situation.
2) Sometimes my character jumps be himself at the beginning of stage. Not a big deal, of course, but still confusing.
3) I doubt that someone would really use sword to cut something before own back – just try it by itself and you would understand what I’m talking ‘bout).
4) As I already mentioned, hook’s sparking aren’t really fits well here – there a lot more ways to give it energetic appearance? especially considering that there no sparking ray exists).
5) "Briefings" shoudn’t really occupy whole width of output area – just add some frame to it. Background other than plan black screen wouldn’t hurt as well.

P.S. And no, it isn't really unique at all. Proofs needed) ?

I cant believed i rated this one, again sorry lol, its a great game XD mistakes happen XD

I loved it, very fun, very creative. My only suggestion is to get rid of "leap of faith" jumps, especially when the player can land on spikes without know it.

Very enjoyable, well conceived mechanics applied very well. Good job!

Excellent. Very well made game. Got to level 6 and had to run. Would love to see some music added to the game however. Sound effects were great.

Awesome mechanics and sound effects, but I think the level design could use a bit more variety. Great job, deserves a 4.5, I will round up because I love you :P